Receivables [Abstract]
Accounts receivable
Accounts Receivable, Gross, Current
Less: Allowance for doubtful accounts
Allowance for Doubtful Accounts Receivable, Current
Total, net
Accounts Receivable, Net, Current
Related Party Transactions [Abstract]
Sales to affiliates
Revenue from Related Parties
Payments to affiliates
Related Party Transaction, Amounts of Transaction
Due from affiliates
Due from Related Parties
Due to affiliates
Due to Related Parties
Income Tax Disclosure [Abstract]
Federal statutory rate
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
State income taxes, net of Federal benefit
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent
Domestic manufacturing deduction
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent
Excess tax benefits
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent
Other
Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent
Effective tax rate
Effective Income Tax Rate Reconciliation, Percent
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]
Title of Individual [Axis]
Title of Individual [Axis]
Relationship to Entity [Domain]
Relationship to Entity [Domain]
Director
Director [Member]
Triggering Event [Axis]
Triggering Event [Axis]
Triggering Event [Axis]
Triggering Event [Domain]
Triggering Event [Domain]
[Domain] for Triggering Event [Axis]
Options Granted on or after May 25, 2004
Options Granted on or after May 25, 2004 [Member]
Options Granted on or after May 25, 2004 [Member]
Award Type [Axis]
Award Type [Axis]
Equity Award [Domain]
Equity Award [Domain]
Restricted Stock
Restricted Stock [Member]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Minimum
Minimum [Member]
Maximum
Maximum [Member]
Plan Name [Axis]
Plan Name [Axis]
Plan Name [Domain]
Plan Name [Domain]
2007 Long-Term Incentive Plan
2007 Long-Term Incentive Plan
-- None. No documentation exists for this element. --
2016 Long-Term Incentive Plan
2016 Long-Term Incentive Plan [Member]
2016 Long-Term Incentive Plan [Member]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Retained Earnings
Retained Earnings [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock authorized to be issued under plan (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized
Exercise price of shares granted may not be less than fair market value (percentage)
Exercise price of shares granted may not be less than fair market value (percentage)
The exercise price of granted shares may not be below this percentage of fair market value under the terms of the stock option plans.
Annual vesting period
Share-based Compensation Arrangement by Share-based Payment Award, Annual Vesting, Percentage
Share-based Compensation Arrangement by Share-based Payment Award, Annual Vesting, Percentage
Unrecognized pre-tax compensation cost
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized
Weighted average recognition period (in years)
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition
Total intrinsic value of options exercised during period
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value
Cash received from options exercised during period
Proceeds from Stock Options Exercised
Earnings Per Share [Abstract]
Earnings Per Share
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information
Cash Flow, Supplemental Disclosures [Text Block]
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of period (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Granted (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period
Vested (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period
Forfeited (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period
Unvested, end of period (in shares)
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]
Unvested, beginning of period (weighted average grant date fair value)
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)
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)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value
Forfeited (weighted average grant date fair value)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value
Unvested, end of period (weighted average grant date fair value)
Revenue from Contract with Customer [Abstract]
Revenue Recognition
Revenue from Contract with Customer [Text Block]
Document And Entity Information
-- None. No documentation exists for this element. --
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
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
Document Fiscal Period Focus
Document Fiscal Period Focus
Document Fiscal Year Focus
Document Fiscal Year Focus
Schedule of Disaggregation of Revenue
Disaggregation of Revenue [Table Text Block]
Stockholders' Equity Note [Abstract]
Schedule of Share Repurchases
Schedule of Share Repurchases [Table Text Block]
Schedule of Share Repurchases [Table Text Block]
Schedule of Dividends Payable
Schedule of Dividends Payable [Table Text Block]
Stockholders' Equity
Stockholders' Equity Note Disclosure [Text Block]
Debt Disclosure [Abstract]
Revolving Credit Facility
Debt Disclosure [Text Block]
Payables and Accruals [Abstract]
Accrued Liabilities
Accounts Payable and Accrued Liabilities Disclosure [Text Block]
Directors and Officers
Director and Officers [Member]
Director and Officers [Member]
Employees
2007 Long-Term Incentive Plan Employees [Member]
2007 Long-Term Incentive Plan Employees [Member]
Expected dividend rate
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Expected Dividend
Expected volatility
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Risk-free interest rate
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Expected life
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term
Investments [Abstract]
Schedule of Investments [Table]
Schedule of Investments [Table]
Schedule of Investments [Line Items]
Schedule of Investments [Line Items]
Certificates of deposit
Certificates of Deposit, at Carrying Value
Certificates of deposit interest rate, lower range
Certificates Of Deposit Interest Rate Lower Range
Lower range of interest rates for certificates of deposit.
Certificates of deposit interest rate, upper range
Certificates Of Deposit Interest Rate Upper Range
Upper range of interest rates for certificates of deposit.
Certificates of deposit maturity dates
Certificates of deposit maturity dates
Maturity dates of certificates of deposits.
Investments held to maturity
Held-to-maturity Securities
Investments maturity dates
Investments maturity dates
The perod of time during which held to maturity securities mature.
Investments
Investment Holdings [Text Block]
Supplemental disclosure:
Supplemental Cash Flow Information [Abstract]
Interest paid
Interest Paid
Income taxes paid
Income Taxes Paid, Net
Non-cash investing and financing activities:
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Non-cash capital expenditures
Change in Capital Expenditures Incurred But Not Yet Paid
Change in Capital Expenditures Incurred But Not Yet Paid
Dividends declared
Dividends, Cash
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table]
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table]
Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Axis]
Exercise Price Range [Axis]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain]
$4.54 - $32.80
Exercise Price Range 1 [Member]
Exercise Price Range 1 [Member]
$32.85 - $34.10
Exercise Price Range 2 [Member]
Exercise Price Range 2 [Member]
$34.15 - $39.00
Exercise Price Range 3 [Member]
Exercise Price Range 3 [Member]
$4.54 - $22.76
Exercise Price Range 4 [Member]
Exercise Price Range 4 [Member]
$23.57 - $32.80
Exercise Price Range 5 [Member]
Exercise Price Range 5 [Member]
$32.85 - $36.70
Exercise Price Range 6 [Member]
Exercise Price Range 6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit
Range of exercise prices, upper range
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit
Number of shares vested and exercisable
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options
Options vested and exercisable weighted average remaining contractual life
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term
Options vested and exercisable weighted average exercise price
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price
Options vested and exercisable intrinsic value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value
Schedule of Components of Income Tax Expense (Benefit)
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Schedule of Effective Income Tax Rate Reconciliation
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Share-Based Compensation
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]
Options
AllocatedShareBasedCompensationExpenseStockOptions
Share-based compensation expense related to options.
Restricted stock
AllocatedShareBasedCompensationExpenseRestrictedStock
Share-based compensation expense related to resticted stock.
Total
Allocated Share-based Compensation Expense
Income Taxes
Income Tax Disclosure [Text Block]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period
Allowance for Doubtful Accounts Receivable
Provisions for losses on accounts receivables, net of recoveries
Allowance for Doubtful Accounts Receivable, Period Increase (Decrease)
Balance, end of period
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [Table]
Business Acquisition [Axis]
Business Acquisition [Axis]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
WattMaster
WattMaster Controls, Inc. [Member]
WattMaster Controls, Inc. [Member]
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Payments to acquire businesses
Payments to Acquire Businesses, Gross
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Accounts receivable
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables
Inventories
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory
Property, plant and equipment
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment
Goodwill
Goodwill
Assumed current liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities
Consideration paid
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net
Related Parties
Related Party Transactions Disclosure [Text Block]
Accounts Receivable
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]
Accounts Receivable
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Allowance for Doubtful Accounts
Accounts Receivable (Allowance)
Tabular disclosure of activity in the allowance for doubtful accounts receivable account.
Supplemental Cash Flow Information
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Statement of Financial Position [Abstract]
Assets
Assets [Abstract]
Current assets:
Assets, Current [Abstract]
Cash and cash equivalents
Cash and Cash Equivalents, at Carrying Value
Investments held to maturity at amortized cost
Held-to-maturity Securities, Current
Accounts receivable, net
Income tax receivable
Income Taxes Receivable, Current
Notes receivable
Notes, Loans and Financing Receivable, Net, Current
Inventories, net
Inventory, Net
Prepaid expenses and other
Prepaid Expense and Other Assets, Current
Total current assets
Assets, Current
Property, plant and equipment:
Property, Plant and Equipment [Abstract]
Land
Land
Buildings
Buildings and Improvements, Gross
Machinery and equipment
Machinery and Equipment, Gross
Furniture and fixtures
Furniture and Fixtures, Gross
Total property, plant and equipment
Property, Plant and Equipment, Gross
Less: Accumulated depreciation
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Property, plant and equipment, net
Property, Plant and Equipment, Net
Note receivable
Notes, Loans and Financing Receivable, Net, Noncurrent
Total assets
Assets
Liabilities and Stockholders' Equity
Liabilities and Equity [Abstract]
Liabilities
Liabilities [Abstract]
Current liabilities:
Liabilities, Current [Abstract]
Revolving credit facility
Line of Credit, Current
Accounts payable
Accounts Payable, Current
Accrued liabilities
Accrued Liabilities, Current
Total current liabilities
Liabilities, Current
Deferred revenue
Deferred Revenue, Noncurrent
Deferred tax liabilities
Deferred Tax Liabilities, Net, Noncurrent
Donations
Other Accrued Liabilities, Noncurrent
Commitments and contingencies
Commitments and Contingencies
Stockholders' equity:
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, $.001 par value, 5,000,000 shares authorized, no shares issued
Preferred Stock, Value, Issued
Common stock, $.004 par value, 100,000,000 shares authorized, 52,394,349 and 52,422,801 issued and outstanding at March 31, 2018 and December 31, 2017, respectively
Common Stock, Value, Issued
Additional paid-in capital
Additional Paid in Capital
Retained earnings
Retained Earnings (Accumulated Deficit)
Total stockholders' equity
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Total liabilities and stockholders' equity
Liabilities and Equity
Net income
Net Income (Loss) Attributable to Parent
Basic weighted average shares (in shares)
Weighted Average Number of Shares Outstanding, Basic
Effect of dilutive stock options and restricted stock (in shares)
Weighted Average Number Diluted Shares Outstanding Adjustment
Diluted weighted average shares (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Basic (usd per share)
Earnings Per Share, Basic
Diluted (usd per share)
Earnings Per Share, Diluted
Anti-dilutive shares (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Schedule of Gain (Loss) on Investments [Table]
Schedule of Gain (Loss) on Investments [Table]
Investments by Category [Axis]
Investments by Category [Axis]
Marketable Securities and Investments Held at Cost [Domain]
Marketable Securities and Investments Held at Cost [Domain]
Current assets
Held-to-maturity Securities, Current [Member]
Held-to-maturity Securities, Current [Member]
Non current assets
Held-to-maturity Securities, Noncurrent [Member]
Held-to-maturity Securities, Noncurrent [Member]
Gain (Loss) on Investments [Line Items]
Gain (Loss) on Investments [Line Items]
Amortized Cost
Gross Unrealized Gain
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain
Gross Unrealized (Loss)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss
Fair Value
Held-to-maturity Securities, Fair Value
Warranty
Product Warranty Accrual, Current
Due to representatives
Accrued Sales Commission, Current
Payroll
Employee-related Liabilities, Current
Profit sharing
Accrued Profit Sharing, Current
Accrued Profit Sharing, Current
Worker's compensation
Workers' Compensation Liability, Current
Medical self-insurance
Self Insurance Reserve, Current
Customer prepayments
Customer Advances and Deposits, Current
Donations
Donations, Current
Donations, Current
Employee vacation time
Accrued Employee Benefits, Current
Other
Other Accrued Liabilities, Current
Total
Statement of Cash Flows [Abstract]
Operating Activities
Net Cash Provided by (Used in) Operating Activities [Abstract]
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation
Depreciation
Amortization of bond premiums
Amortization
Provision for losses on accounts receivable, net of adjustments
Provision for excess and obsolete inventories
Inventory Write-down
Share-based compensation
Share-based Compensation
(Gain) loss on disposal of assets
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property
Foreign currency transaction gain
Foreign Currency Transaction Gain (Loss), Realized
Interest income on note receivable
InterestIncomeNoteReceivable
Interest income related to note receivable.
Deferred
Deferred Income Tax Expense (Benefit)
Changes in assets and liabilities:
Increase (Decrease) in Operating Capital [Abstract]
Accounts receivable
Increase (Decrease) in Accounts Receivable
Income taxes
Increase (Decrease) in Income Taxes
Inventories
Increase (Decrease) in Inventories
Prepaid expenses and other
Increase (Decrease) in Prepaid Expense and Other Assets
Accounts payable
Increase (Decrease) in Accounts Payable
Deferred revenue
Increase (Decrease) in Deferred Revenue
Accrued liabilities and donations
Increase (Decrease) in Accrued Liabilities
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
Investing Activities
Net Cash Provided by (Used in) Investing Activities [Abstract]
Capital expenditures
Payments to Acquire Productive Assets
Cash paid in business combination
Proceeds from sale of property, plant and equipment
Proceeds from Sale of Property, Plant, and Equipment
Investment in certificates of deposits
Payments to Acquire Other Investments
Maturities of certificates of deposits
Proceeds from Sale and Maturity of Other Investments
Purchases of investments held to maturity
Payments to Acquire Held-to-maturity Securities
Maturities of investments
Proceeds from Sale, Maturity and Collection of Investments
Proceeds from called investments
Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities
Principal payments from note receivable
Proceeds from Collection of Notes Receivable
Net cash (used in) provided by investing activities
Net Cash Provided by (Used in) Investing Activities
Financing Activities
Net Cash Provided by (Used in) Financing Activities [Abstract]
Stock options exercised
Repurchase of stock
Payments for Repurchase of Equity
Employee taxes paid by withholding shares
Payments Related to Tax Withholding for Share-based Compensation
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
Net (decrease) increase 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
Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning of period (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number
Granted (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures
Exercised (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period
Forfeited or Expired (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period
Outstanding, end of period (in shares)
Exercisable, end of period (in shares)
Weighted Average Exercise Price [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (weighted average exercise price)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Granted (weighted average exercise price)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price
Exercised (weighted average exercise price)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price
Forfeited or Expired (weighted average exercise price)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price
Outstanding, end of period (weighted average exercise price)
Exercisable, end of period (weighted average exercise price)
Statement of Stockholders' Equity [Abstract]
Statement [Table]
Statement [Table]
Common Stock
Common Stock [Member]
Paid-in Capital
Additional Paid-in Capital [Member]
Statement [Line Items]
Statement [Line Items]
Balance
Balance (in shares)
Shares, Outstanding
Stock options exercised and restricted stock awards granted
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures
Stock options exercised and restricted stock awards granted (in shares)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures
Share-based compensation
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition
Stock repurchased and retired
Stock Repurchased and Retired During Period, Value
Stock repurchased and retired (in shares)
Stock Repurchased and Retired During Period, Shares
Balance
Balance (in shares)
Guarantees [Abstract]
Movement in Standard Product Warranty Accrual [Roll Forward]
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance, beginning of period
Standard Product Warranty Accrual
Payments made
Standard Product Warranty Accrual, Decrease for Payments
Provisions
Standard Product Warranty Accrual, Increase for Warranties Issued
Balance, end of period
Warranty expense
Product Warranty Expense
Schedule of Shareholders' Equity [Table]
Schedule of Shareholders' Equity [Table]
Schedule of Shareholders' Equity [Table]
Share Repurchase Program [Axis]
Share Repurchase Program [Axis]
Share Repurchase Program [Domain]
Share Repurchase Program [Domain]
2010 Stock Repurchase Program
2010 Stock Repurchase Program [Member]
2010 Stock Repurchase Program [Member]
2005 401(k) Stock Repurchase Program
2005 401(k) Stock Repurchase Program [Member]
2005 401(k) Stock Repurchase Program [Member]
2006 Director and Officer Repurchase Program
2006 Director and Officer Repurchase Program [Member]
2006 Director and Officer Repurchase Program [Member]
Dividends [Axis]
Dividends [Axis]
Dividends [Domain]
Dividends [Domain]
Dividend Declared
Dividend Declared [Member]
Schedule of Shareholders' Equity [Line Items]
Schedule of Shareholders' Equity [Line Items]
[Line Items] for Schedule of Shareholders' Equity [Table]
Stock repurchase program, authorized amount
Stock Repurchase Program, Authorized Amount
Stock repurchase program amount authorized (in shares)
Stock Repurchase Program, Number of Shares Authorized to be Repurchased
Stock repurchased during period (in shares)
Treasury Stock, Shares, Acquired
Aggregate price of shares repurchased since inception
Treasury Stock, Value, Acquired, Cost Method
Average price of shares repurchased since inception (per share)
Treasury Stock Acquired, Average Cost Per Share
Cash dividends declared per common share
Common Stock, Dividends, Per Share, Declared
Preferred stock, par value
Preferred Stock, Par or Stated Value Per Share
Preferred stock, shares authorized
Preferred Stock, Shares Authorized
Preferred stock, shares issued
Preferred Stock, Shares Issued
Common stock, par value
Common Stock, Par or Stated Value Per Share
Common stock, shares authorized
Common Stock, Shares Authorized
Common stock, shares issued
Common Stock, Shares, Issued
Common stock, shares outstanding
Common Stock, Shares, Outstanding
Earnings Per Share
Earnings Per Share [Text Block]
Amortized Cost and Estimated Fair Value of Investments Held to Maturity
Schedule of Unrealized Loss on Investments [Table Text Block]
Product warranty accrual, minimum length
Product Warranty Accrual, Minimum Length
Product Warranty Accrual, Minimum Length
Product warranty accrual, maximum length
Product Warranty Accrual, Maximum Length
Product Warranty Accrual, Maximum Length
Income Statement [Abstract]
Net sales
Sales Revenue, Goods, Net
Cost of sales
Cost of Goods Sold
Gross profit
Gross Profit
Selling, general and administrative expenses
Selling, General and Administrative Expense
Income from operations
Operating Income (Loss)
Interest income, net
Investment Income, Interest
Other (expense) income, net
Other Nonoperating Income (Expense)
Income tax provision
Income Tax Expense (Benefit)
Net income
Earnings per share:
Weighted average shares outstanding:
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Basic (in shares)
Diluted (in shares)
Schedule of Related Party Transactions
Schedule of Related Party Transactions [Table Text Block]
Inventory Disclosure [Abstract]
Inventories
Schedule of Inventory, Current [Table Text Block]
Inventories (Allowance)
Inventories (Allowance)
Tabular disclosure of activity in the allowance for excess and obsolete inventory account.
Warranties
Product Warranty Disclosure [Text Block]
Schedule of Acquisition
Schedule of Business Acquisitions, by Acquisition [Table Text Block]
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Abstract]
Use of Estimates
Use of Estimates, Policy [Policy Text Block]
Business Combination Measurement Period
Business Combinations Policy [Policy Text Block]
Fair Value Measurements
Fair Value Measurement, Policy [Policy Text Block]
Goodwill
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]
Recent Accounting Pronouncements
New Accounting Pronouncements, Policy [Policy Text Block]
Accrued Liabilities
Schedule of Accrued Liabilities [Table Text Block]
Business Combination, Separately Recognized Transactions [Table]
Business Combination, Separately Recognized Transactions [Table]
Business Combination, Separately Recognized Transactions [Line Items]
Business Combination, Separately Recognized Transactions [Line Items]
Acquisition
Business Combination Disclosure [Text Block]
Options
Options
Fair value of options awarded during the period.
Restricted stock
Restricted stock
Fair value of restricted stock awarded during period.
Total
ShareBasedCompensationArrangementByShareBasedPaymentAwardTotalAwardedInPeriodFairValue
Total fair value of options and restricted stock awarded during period.
Disaggregation of Revenue [Table]
Disaggregation of Revenue [Table]
Products and Services [Axis]
Products and Services [Axis]
Products and Services [Domain]
Products and Services [Domain]
Rooftop Units
Rooftop Units [Member]
Rooftop Units [Member]
Condensing Units
Condensing Units [Member]
Condensing Units [Member]
Air Handlers
Air Handlers [Member]
Air Handlers [Member]
Outdoor Mechanical Rooms
Outdoor Mechanical Rooms [Member]
Outdoor Mechanical Rooms [Member]
Water Source Heat Pumps
Water Source Heat Pumps [Member]
Water Source Heat Pumps [Member]
Other
Other Product and Services [Member]
Other Product and Services [Member]
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Line Items]
Net Sales
Revenue from Contract with Customer, Including Assessed Tax
Total Units
Revenue from Contract with Customer, Including Assessed Tax, Number of Units
Revenue from Contract with Customer, Including Assessed Tax, Number of Units
Inventories
Inventory Disclosure [Text Block]
General
Basis of Presentation and Significant Accounting Policies [Text Block]
Expected effective income tax rate for the year
Expected Effective Income Tax Rate, Continuing Operations
Expected Effective Income Tax Rate, Continuing Operations
Warranty
Schedule of Product Warranty Liability [Table Text Block]
Payments to representatives
Sales Commissions and Fees
Extended product warranties, minimum length
Extended Product Warranties, Minimum Length
Extended Product Warranties, Minimum Length
Extended product warranties, maximum length
Extended Product Warranties, Maximum Length
Extended Product Warranties, Maximum Length
Raw materials
Inventory, Raw Materials, Gross
Work in process
Inventory, Work in Process, Gross
Finished goods
Inventory, Finished Goods, Gross
Inventory, gross
Inventory, Gross
Less: Allowance for excess and obsolete inventories
Inventory Valuation Reserves
Total, net
Current
Current Income Tax Expense (Benefit)
Provision (benefit) for income taxes
Summary of Stock Option Assumptions
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Summary of Stock Options Outstanding
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]
Summary of Stock Option Activity
Share-based Compensation, Stock Options, Activity [Table Text Block]
Summary of Unvested Restricted Stock Awards
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]
Summary of Grant Date Fair Value of Awards During Period
Summary of Grant Date Fair Value of Awards During Period
Tabular disclosure of the grant date fair value of options and restricted sotck.
Summary of Share-Based Compensation Expense
Summary of Share-Based Compensation Expense
Tabular disclosure of share based compensation related to options and restricted stock.
Summary of Income Tax Benefit Related to Share-Based Compensation
Summary of Income Tax Benefit Related to Share-Based Compensation
Tabular disclosure of tax benefit from share based compensation related to options and restricted stock.
Inventory Valuation Reserves [Roll Forward]
Inventory Valuation Reserves [Roll Forward]
Inventory Valuation Reserves [Roll Forward]
Balance, beginning of period
Provisions for excess and obsolete inventories
Provisions for excess and obsolete inventories
Charge to expense for inventory that is expected to be excess or obsolete.
Inventories written off
Inventory Valuation Reserves Write Offs
Inventory that is written off due to being excess or obsolete.
Balance, end of period
Line of Credit Facility [Table]
Line of Credit Facility [Table]
Credit Facility [Axis]
Credit Facility [Axis]
Credit Facility [Domain]
Credit Facility [Domain]
Revolving Credit Facility
Revolving Credit Facility [Member]
Variable Rate [Axis]
Variable Rate [Axis]
Variable Rate [Domain]
Variable Rate [Domain]
LIBOR
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Credit facility maximum borrowings
Line of Credit Facility, Maximum Borrowing Capacity
Standby letter of credit
Standby letter of credit
Amount of standby letter of credit outstanding under the revolving credit agreement.
Borrowings available under the revolving credit facility
Line of Credit Facility, Current Borrowing Capacity
Frequency of periodic payment
Line of Credit Facility, Frequency of Payments
Stated percentage
Debt Instrument, Interest Rate, Stated Percentage
Actual net worth for compliance
Actual Net Worth for Compliance
Actual Net Worth for Compliance
Minimum net worth required for compliance
Minimum Net Worth Required for Compliance
Ratio of total liability to net worth
Ratio of Total Liability to Net Worth
Ratio of Total Liability to Net Worth
Maximum ratio of total liability to net worth for compliance
Maximum Ratio of Total Liability to Net Worth Required for Compliance
Maximum Ratio of Total Liability to Net Worth Required for Compliance
Borrowings outstanding under revolving credit facility
Long-term Line of Credit
Fees associated with unused portion of committed amount
Line of Credit Facility, Commitment Fee Amount
Options
EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpenseStockOptions
Tax benefit from share-based compensation related to options.
Restricted stock
Employee Service Share Based Compensation Tax (Expense) Benefit From Compensation Expense Restricted Stock
Employee Service Share Based Compensation Tax (Expense) Benefit From Compensation Expense Restricted Stock
Total
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense