Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships [Member] Customer Relationships [Member] Trademarks [Member] Trademarks [Member] Trade secrets [Member] Trade Secrets [Member] Carrier relationships [Member] Carrier Relationships [Member] Carrier relationships. Other finite-life intangible assets [Member] Other Finite Life Intangible Assets [Member] Other finite-life intangible assets. Summary of Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite-life intangible assets, Gross Carrying Amount Finite-Lived Intangible Assets, Gross Finite-life intangible assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Total finite-life intangible assets, Net Finite-Lived Intangible Assets, Net Indefinite-life intangible assets gross Indefinite Lived Intangible Assets Excluding Goodwill Gross Indefinite-life intangible assets gross. Indefinite-life intangible assets, Accumulated Amortization Indefinite Intangible Assets Accumulated Amortization Indefinite-life intangible assets amortization. Indefinite-life intangible assets Indefinite-Lived Intangible Assets (Excluding Goodwill) Total Intangible Assets, Gross Intangible Assets, Gross (Excluding Goodwill) Intangible assets, Accumulated Amortization Intangible Assets Accumulated Amortization Intangible assets accumulated amortization. Total intangible assets, net Intangible Assets, Net (Excluding Goodwill) Inventory Disclosure [Abstract] Inventories Inventory Disclosure [Text Block] Equity [Abstract] Summary of Accumulated other comprehensive loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents and Investments Cash and Cash Equivalents Disclosure [Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Performance-Based Restricted Stock [Member] Performance Shares [Member] Restricted Stock Awards [Member] Restricted Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Restricted stock activity Restricted Stock Activity [Abstract] Restricted stock activity. Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Beginning Balance (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited or expired (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Ending Balance (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Beginning Balance, Weighted average grant date fair value (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted, Weighted average grant date fair value (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested, Weighted average grant date fair value (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited or expired, Weighted average grant date fair value (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Ending Balance, Weighted average grant date fair value (usd per share) Finished goods (LIFO basis) LIFO Inventory Amount Increase (decrease) in LIFO reserve Inventory, LIFO Reserve, Period Charge Earnings Per Share [Abstract] Shares or stock options excluded from the calculation of diluted EPS Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of intangible assets and goodwill Schedule of Intangible Assets and Goodwill [Table Text Block] Stock Options [Member] Employee Stock Option [Member] Restricted Stock Units [Member] Restricted Stock Units (RSUs) [Member] Compensation expense Allocated Share-based Compensation Expense Range of restricted stock to be issued minimum (shares) Range of Restricted Stock to be Issued Minimum Range of restricted stock to be issued minimum. Range of restricted stock to be issued maximum (shares) Range of Restricted Stock to be Issued Maximum Range of restricted stock to be issued maximum. Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Restricted stock awards outstanding (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Number Restricted stock awards, weighted average exercise price (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Exercise Price Stock options exercised Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Weighted average exercise price (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Summary of basic and diluted EPS Weighted Average Number of Shares Outstanding, Diluted [Abstract] Weighted-average common shares outstanding-basic (shares) Weighted Average Number of Shares Outstanding, Basic Dilutive impact of stock options, performance units, and restricted stock (shares) Weighted Average Number Diluted Shares Outstanding Adjustment Weighted-average common shares outstanding-diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Earnings per Share Earnings Per Share [Text Block] Summary of Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized gain (loss) on: Other Comprehensive Income (Loss), Net of Tax [Abstract] Available-for-sale investments Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Post-retirement plan liability Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Share-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Industrial [Member] Industrial [Member] Industrial. Water Treatment [Member] Water Treatment [Member] Water treatment. Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Revenue, Net Revenue, Net Gross profit Gross Profit Selling, General and Administrative Expense Selling, General and Administrative Expense Operating income Operating Income (Loss) Summary of performance-based restricted stock units Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Goodwill Goodwill Number of reportable segments (segments) Number of Reportable Segments Intersegment sales Intersegment Sales Intersegment sales. Number of operating segments aggregated (segments) Number of Operating Segments Aggregated Number of operating segments aggregated. Number of customer representing 10 percent or more of revenue (customers) Entity Wide Revenue Major Customer Number of Customers Entity wide revenue major customer number of customers. Statement of Financial Position [Abstract] Allowance for doubtful accounts, trade receivables Allowance for Doubtful Accounts Receivable, Current Intangible assets accumulated amortization Shares authorized (shares) Common Stock, Shares Authorized Common stock, par value (usd per share) Common Stock, Par or Stated Value Per Share Common Stock, Shares, Issued Common Stock, Shares, Issued Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Share Repurchase Program [Abstract] Share Repurchase Program [Abstract] Share Repurchase Program Stockholders' Equity Note Disclosure [Text Block] Summary of Inventories Schedule of Inventory, Current [Table Text Block] Summary of financial assets and liabilities measured at fair value Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Summary of basic and diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Business Combinations [Abstract] Business Combination Disclosure [Text Block] Business Combination Disclosure [Text Block] Summary of Inventories Inventory, Net [Abstract] Inventory (FIFO basis) Inventory, Finished Goods, Gross LIFO reserve Inventory, LIFO Reserve Net inventory Inventory, Net Segment Information Segment Reporting Disclosure [Text Block] Stock Repurchase Program, Number of Shares Authorized to be Repurchased Stock Repurchase Program, Number of Shares Authorized to be Repurchased Stock Repurchased During Period, Shares Stock Repurchased During Period, Shares Stock Repurchased During Period, Value Stock Repurchased During Period, Value Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive income (loss), net of tax: Unrealized gain (loss) on available-for-sale investments Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Unrealized gain (loss) on post-retirement liability Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Income Statement [Abstract] Sales Cost of sales Cost of Goods and Services Sold Gross profit Selling, general and administrative expenses Operating income Interest income (expense), net Interest Income (Expense), Net Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax provision Income Tax Expense (Benefit) Net income Weighted average number of shares outstanding - basic Weighted average number of shares outstanding - diluted Basic earnings per share Earnings Per Share, Basic [Abstract] Basic earnings per share (usd per share) Earnings Per Share, Basic Diluted earnings per share Earnings Per Share, Diluted [Abstract] Diluted earnings per share (usd per share) Earnings Per Share, Diluted Cash dividends declared per common share (usd per share) Common Stock, Dividends, Per Share, Declared Commitments and Contingencies Disclosure [Abstract] Litigation, Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Summary of Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Document and Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Schedule of Cash and Cash Equivalents [Table] Schedule of Cash and Cash Equivalents [Table] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Cash [Member] Cash [Member] Certificates of deposit [Member] Certificates of Deposit [Member] Municipal bonds [Member] Municipal Bonds [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Total [Member] Estimate of Fair Value Measurement [Member] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Summary of financial assets and liabilities measured at fair value Cash, Cash Equivalents, and Short-term Investments [Abstract] Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash/Certificates of deposit/Money market securities Cash and Cash Equivalents, Fair Value Disclosure Fair Value, Inputs, Level 2 [Member] Maturities period of certificates of deposit minimum Maturities Period of Certificates of Deposit Minimum Maturities period of certificates of deposit and municipal bonds minimum Maturities period of certificates of deposit maximum Maturities Period of Certificates of Deposit Maximum Maturities period of certificates of deposit maximum. Available-for-sale Securities, Current Available-for-sale Securities, Current Available-for-sale Securities, Noncurrent Available-for-sale Securities, Noncurrent ASSETS Assets [Abstract] CURRENT ASSETS: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Investments available-for-sale Marketable Securities Trade receivables — less allowance for doubtful accounts: $375 as of December 28, 2014 and $477 as of March 30, 2014 Accounts Receivable, Net, Current Inventories Income Taxes Receivable, Current Income Taxes Receivable, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current PROPERTY, PLANT AND EQUIPMENT: Property, Plant and Equipment [Abstract] Property, plant and equipment Property, Plant and Equipment, Gross Less accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Net property, plant, and equipment Property, Plant and Equipment, Net Goodwill Intangible assets — less accumulated amortization: $3,671 as of December 28, 2014 and $3,069 as of March 30, 2014 Long-term investments Long-term Investments Other Other Assets, Noncurrent Total other assets Other Assets Total assets Assets LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] CURRENT LIABILITIES: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Dividends payable Dividends Payable, Current Accrued payroll and employee benefits Employee-related Liabilities, Current Deferred income taxes Deferred Tax Liabilities, Net, Current Income tax payable Accrued Income Taxes, Current Other current liabilities Other Accrued Liabilities, Current Total current liabilities Liabilities, Current PENSION WITHDRAWAL LIABILITY Defined Benefit Pension Plan, Liabilities, Noncurrent OTHER LONG-TERM LIABILITIES Other Liabilities, Noncurrent DEFERRED INCOME TAXES Deferred Tax Liabilities, Net, Noncurrent Total liabilities Liabilities COMMITMENTS AND CONTINGENCIES Commitments and Contingencies SHAREHOLDERS’ EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Common stock; authorized: 30,000,000 shares of $0.05 par value; 10,569,026 and 10,562,400 shares issued and outstanding as of December 28, 2014 and March 30, 2014, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Total shareholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and shareholders’ equity Liabilities and Equity Statement of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income Reconciliation to cash flows: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Deferred income taxes Deferred Income Tax Expense (Benefit) Stock compensation expense Share-based Compensation Loss from property disposals Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Changes in operating accounts providing (using) cash: Increase (Decrease) in Operating Capital [Abstract] Trade receivables Increase (Decrease) in Accounts Receivable Inventories Increase (Decrease) in Inventories Accounts payable Increase (Decrease) in Accounts Payable Accrued liabilities Increase (Decrease) in Accrued Liabilities Income tax payable Increase (Decrease) in Income Taxes Payable Other Increase (Decrease) in Other Operating Assets and Liabilities, Net Net Cash Provided by (Used in) Operating Activities Net Cash Provided by (Used in) Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Additions to property, plant, and equipment Payments to Acquire Property, Plant, and Equipment Purchases of investments Payments to Acquire Investments Sale and maturities of investments Proceeds from Sale and Maturity of Marketable Securities Acquisitions Payments to Acquire Businesses, Net of Cash Acquired Proceeds from property disposals Proceeds from Sale of Property, Plant, and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Cash dividends paid Payments of Ordinary Dividends, Common Stock New Shares Issued Proceeds from Stock Plans Shares Surrendered for payroll taxes Payments Related to Tax Withholding for Share-based Compensation Proceeds from the exercise of stock options Proceeds from Stock Options Exercised Excess tax benefit from share-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Shares repurchased Payments for Repurchase of Equity Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities NET DECREASE IN CASH AND CASH EQUIVALENTS Cash and Cash Equivalents, Period Increase (Decrease) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD CASH AND CASH EQUIVALENTS, END OF PERIOD SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION Supplemental Cash Flow Information [Abstract] Cash paid for income taxes Income Taxes Paid, Net Noncash investing activities - Capital expenditures in accounts payable Capital Expenditures Incurred but Not yet Paid Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Customer Relationships [Member] Trade Names [Member] Trade Names [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] The Dumont Company, Inc. TheDumontCompany, Inc. [Member] TheDumontCompany, Inc. [Member] Advance Chemical Solutions, Inc. [Member] Advance Chemical Solutions, Inc. [Member] Advance Chemical Solutions, Inc. [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Payments to Acquire Businesses, Net of Cash Acquired Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Contingent Consideration Measurement Period Contingent Consideration Measurement Period Contingent Consideration Measurement Period Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period