AAON (AAON) 10-K 23 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Feb. 16, 2017	Jun. 30, 2016
Document And Entity Information
Entity Registrant Name	AAON INC
Entity Central Index Key	824,142
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		52,641,334
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,016
Entity Public Float			$ 1,093.9

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 24,153	$ 7,908
Certificates of deposit	5,512	10,080
Held-to-maturity Securities, Current	14,083	12,444
Accounts receivable, net	43,001	50,024
Income tax receivable	6,239	4,702
Note receivable	25	23
Inventories, net	47,352	38,499
Prepaid expenses and other	616	533
Total current assets	140,981	124,213
Property, plant and equipment:
Land	2,233	2,233
Buildings	78,806	68,806
Machinery and equipment	158,216	143,100
Furniture and fixtures	12,783	11,270
Total property, plant and equipment	252,038	225,409
Less: Accumulated depreciation	137,146	124,348
Property, plant and equipment, net	114,892	101,061
Certificates of deposit	0	1,880
Held-to-maturity Securities, Noncurrent	0	5,039
Note receivable, long-term	657	661
Total assets	256,530	232,854
Current liabilities:
Revolving credit facility	0	0
Accounts payable	7,102	6,178
Accrued liabilities	31,940	37,235
Total current liabilities	39,042	43,413
Deferred revenue	1,498	698
Deferred tax liabilities	9,531	8,706
Donations	561	1,119
Commitments and contingencies
Stockholders' equity:
Preferred stock, $.001 par value, 5,000,000 shares authorized, no shares issued
Common stock, $.004 par value, 100,000,000 shares authorized, 52,651,448 and 53,012,363 issued and outstanding at December 31, 2016 and 2015, respectively	211	212
Additional paid-in capital	0	0
Retained earnings	205,687	178,706
Total stockholders' equity	205,898	178,918
Total liabilities and stockholders' equity	$ 256,530	$ 232,854

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Stockholders' equity:
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.004	$ 0.004
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	52,651,448	53,012,363
Common stock, shares outstanding	52,651,448	53,012,363

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net sales	$ 383,977	$ 358,632	$ 356,322
Cost of sales	265,897	249,951	248,059
Gross profit	118,080	108,681	108,263
Selling, general and administrative expenses	38,506	37,438	40,562
Gain on disposal of assets	(20)	(59)	(305)
Income from operations	79,594	71,302	68,006
Interest income, net	292	161	276
Other income (expense), net	105	(124)	(36)
Income before taxes	79,991	71,339	68,246
Income tax provision	26,615	25,611	24,088
Net income	$ 53,376	$ 45,728	$ 44,158
Earnings per share:
Basic (usd per share)	$ 1.01	$ 0.85	$ 0.81
Diluted (usd per share)	1	0.84	0.80
Cash dividends declared per common share	$ 0.24	$ 0.22	$ 0.18
Weighted average shares outstanding:
Basic	52,924,398	54,045,841	54,809,319
Diluted	53,449,754	54,481,484	55,369,016

Consolidated Statements of Inc5

Consolidated Statements of Income (Parenthetical)	Jul. 16, 2014
Income Statement [Abstract]
Stock split, conversion ratio	1.5

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings
Balance (in shares) at Dec. 31, 2013		55,067
Balance at Dec. 31, 2013	$ 164,106	$ 221	$ 0	$ 163,885
Net income	44,158			44,158
Stock options exercised and restricted stock awards granted, including tax benefits (in shares)		463
Stock options exercised and restricted stock awards granted, including tax benefits	2,557	$ 1	2,556
Share-based compensation	2,178		2,178
Stock repurchased and retired (in shares)		(1,488)
Stock repurchased and retired	(29,284)	$ (6)	(4,734)	(24,544)
Dividends	(9,656)			(9,656)
Balance (in shares) at Dec. 31, 2014		54,042
Balance at Dec. 31, 2014	174,059	$ 216	0	173,843
Net income	45,728			45,728
Stock options exercised and restricted stock awards granted, including tax benefits (in shares)		546
Stock options exercised and restricted stock awards granted, including tax benefits	5,240	$ 2	5,238
Share-based compensation	2,891		2,891
Stock repurchased and retired (in shares)		(1,576)
Stock repurchased and retired	(37,143)	$ (6)	(8,129)	(29,008)
Dividends	(11,857)			(11,857)
Balance (in shares) at Dec. 31, 2015		53,012
Balance at Dec. 31, 2015	178,918	$ 212	0	178,706
Net income	53,376			53,376
Stock options exercised and restricted stock awards granted, including tax benefits (in shares)		375
Stock options exercised and restricted stock awards granted, including tax benefits	2,063	$ 2	2,061
Share-based compensation	4,357		4,357
Stock repurchased and retired (in shares)		(736)
Stock repurchased and retired	(20,140)	$ (3)	(6,418)	(13,719)
Dividends	(12,676)			(12,676)
Balance (in shares) at Dec. 31, 2016		52,651
Balance at Dec. 31, 2016	$ 205,898	$ 211	$ 0	$ 205,687

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net income	$ 53,376	$ 45,728	$ 44,158
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	13,035	11,741	11,553
Amortization of bond premiums	249	266	688
Allowance for Doubtful Accounts Receivable, Period Increase (Decrease)	(25)	(48)	(22)
Provision for excess and obsolete inventories	625	178	135
Share-based compensation	4,357	2,891	2,178
Gain on disposition of assets	(20)	(59)	(305)
Foreign currency transaction (gain) loss	(22)	139	74
Interest income on note receivable	(28)	(30)	(36)
Deferred income taxes	825	1,172	(2,111)
Write-off of note receivable	0	0	0
Changes in assets and liabilities:
Accounts receivable	7,048	(5,884)	(5,007)
Income tax receivable	(1,537)	312	(257)
Inventories	(9,478)	(1,059)	(5,613)
Prepaid expenses and other	(83)	76	(305)
Accounts payable	654	(5,109)	3,512
Deferred revenue	417	189	782
Accrued liabilities and donations	(5,470)	4,852	4,094
Net cash provided by operating activities	63,923	55,355	53,518
Investing Activities
Capital expenditures	(26,604)	(20,967)	(16,127)
Proceeds from sale of property, plant and equipment	28	63	319
Investment in certificates of deposits	(4,112)	(6,680)	(9,940)
Maturities of certificates of deposits	10,560	6,098	9,310
Purchase of investments held to maturity	(10,384)	(14,183)	(6,880)
Maturities of investments	10,021	11,408	14,197
Proceeds from called investments	3,514	1,013	3,029
Principal payments from note receivable	52	54	63
Net cash used in investing activities	(16,925)	(23,194)	(6,029)
Financing Activities
Borrowings under revolving credit facility	761	0	0
Payments under revolving credit facility	(761)	0	0
Stock options exercised	2,063	2,795	1,318
Repurchase of stock	(19,317)	(36,558)	(29,066)
Employee taxes paid by withholding shares	(823)	(585)	(218)
Cash dividends paid to stockholders	(12,676)	(11,857)	(9,656)
Net cash used in financing activities	(30,753)	(46,205)	(37,622)
Net increase (decrease) in cash and cash equivalents	16,245	(14,044)	9,867
Cash and cash equivalents, beginning of year	7,908	21,952	12,085
Cash and cash equivalents, end of year	$ 24,153	$ 7,908	$ 21,952

Business Description

Business Description	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Description	Business Description AAON, Inc. is a Nevada corporation which was incorporated on August 18, 1987. Our operating subsidiaries include AAON, Inc., an Oklahoma corporation and AAON Coil Products, Inc., a Texas corporation (collectively, the "Company"). The Consolidated Financial Statements include our accounts and the accounts of our subsidiaries. We are engaged in the engineering, manufacturing, marketing and sale of air conditioning and heating equipment consisting of standard, semi-custom and custom rooftop units, chillers, packaged outdoor mechanical rooms, air handling units, makeup air units, energy recovery units, condensing units, geothermal/water-source heat pumps and coils.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation These financial statements are prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"). The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated. Cash and Cash Equivalents We consider all highly liquid temporary investments with original maturity dates of three months or less to be cash equivalents. Cash and cash equivalents consist of bank deposits and highly liquid, interest-bearing money market funds. The Company's cash and cash equivalents are held in a few financial institutions in amounts that exceed the insurance limits of the Federal Deposit Insurance Corporation. However, management believes that the Company's counterparty risks are minimal based on the reputation and history of the institutions selected. Investments Certificates of Deposit We held $5.5 million and $12.0 million in certificates of deposit at December 31, 2016 and December 31, 2015 , respectively. At December 31, 2016 , the certificates of deposit bear interest ranging from 0.55% to 0.90% per annum and have various maturities ranging from less than two months to approximately 7 months . Investments Held to Maturity At December 31, 2016 , our investments held to maturity were comprised of $14.1 million of corporate notes and bonds with various maturities ranging from less than one month to approximately 6 months . The investments have moderate risk with S&P ratings ranging from AA to BBB-. We record the amortized cost basis and accrued interest of the corporate notes and bonds in the Consolidated Balance Sheets. We record the interest and amortization of bond premium to interest income in the Consolidated Statements of Income. The following summarizes the amortized cost and estimated fair value of our investments held to maturity at December 31, 2016 and December 31, 2015 : Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Fair Value December 31, 2016: (in thousands) Current assets: Investments held to maturity $ 14,083 $ — $ (12 ) $ 14,071 Non current assets: Investments held to maturity — — — — Total $ 14,083 $ — $ (12 ) $ 14,071 December 31, 2015: Current assets: Investments held to maturity $ 12,444 $ — $ (16 ) $ 12,428 Non current assets: Investments held to maturity 5,039 — (17 ) 5,022 Total $ 17,483 $ — $ (33 ) $ 17,450 We evaluate these investments for other-than-temporary impairments on a quarterly basis. We do not believe there was an other-than-temporary impairment for our investments at December 31, 2016 or 2015 . Accounts and Note Receivable Accounts and note receivable are stated at amounts due from customers, net of an allowance for doubtful accounts. We generally do not require that our customers provide collateral. The Company determines its allowance for doubtful accounts by considering a number of factors, including the credit risk of specific customers, the customer’s ability to pay current obligations, historical trends, economic and market conditions and the age of the receivable. Accounts are considered past due when the balance has been outstanding for ninety days past negotiated credit terms. Past due accounts are generally written-off against the allowance for doubtful accounts only after all collection attempts have been exhausted. Concentration of Credit Risk Our customers are concentrated primarily in the domestic commercial and industrial new construction and replacement markets. To date, our sales have been primarily to the domestic market, with foreign sales accounting for approximately 4% , 4% and 6% of revenues for the years ended December 31, 2016 , 2015 and 2014 , respectively. One customer, Texas AirSystems, accounted for 10% or more of our sales during 2016 and 2015 . No customer accounted for 10% or more of our sales during 2014 . No customer accounted for 5% or more of our accounts receivable balance at December 31, 2016 or 2015 . Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, receivables, accounts payable and accrued liabilities approximate fair value because of the short-term maturity of the items. The carrying amount of the Company's revolving line of credit, and other payables, approximate their fair values either due to their short term nature, the variable rates associated with the debt or based on current rates offered to the Company for debt with similar characteristics. Inventories Inventories are valued at the lower of cost or market using the first-in, first-out (“FIFO”) method. Cost in inventory includes purchased parts and materials, direct labor and applied manufacturing overhead. We establish an allowance for excess and obsolete inventories based on product line changes, the feasibility of substituting parts and the need for supply and replacement parts. Property, Plant and Equipment Property, plant and equipment, including significant improvements, are recorded at cost, net of accumulated depreciation. Repairs and maintenance and any gains or losses on disposition are included in operations. Depreciation is computed using the straight-line method over the following estimated useful lives: Buildings 3-40 years Machinery and equipment 3-15 years Furniture and fixtures 3-7 years Impairment of Long-Lived Assets We review long-lived assets for possible impairment when events or changes in circumstances indicate, in management’s judgment, that the carrying amount of an asset may not be recoverable. Recoverability is measured by a comparison of the carrying amount of an asset or asset group to its estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the undiscounted cash flows are less than the carrying amount of the asset or asset group, an impairment loss is recognized for the amount by which the carrying amount of the asset or asset group exceeds its fair value. Research and Development The costs associated with research and development for the purpose of developing and improving new products are expensed as incurred. For the years ended December 31, 2016 , 2015 , and 2014 research and development costs amounted to approximately $12.0 million, $7.5 million , and $6.3 million , respectively. Advertising Advertising costs are expensed as incurred. Advertising expense for the years ended December 31, 2016 , 2015 , and 2014 was approximately $1.4 million, $1.2 million , and $1.0 million , respectively. Shipping and Handling We incur shipping and handling costs in the distribution of products sold that are recorded in cost of sales. Shipping charges that are billed to the customer are recorded in revenues and as an expense in cost of sales. For the years ended December 31, 2016 , 2015 and 2014 shipping and handling fees amounted to approximately $10.3 million, $9.6 million , and $8.5 million , respectively. Income Taxes Income taxes are accounted for under the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the book carrying amounts and the tax basis of assets and liabilities. We establish accruals for unrecognized tax positions when it is more likely than not that our tax return positions may not be fully sustained. The Company records a valuation allowance for deferred tax assets when, in the opinion of management, it is more likely than not that deferred tax assets will not be realized. Share-Based Compensation The Company recognizes expense for its share-based compensation based on the fair value of the awards that are granted. The Company’s share-based compensation plans provide for the granting of stock options and restricted stock. The fair values of stock options are estimated at the date of grant using the Black-Scholes-Merton option valuation model. The use of the Black-Scholes-Merton option valuation model requires the input of subjective assumptions. Measured compensation cost is recognized ratably over the vesting period of the related share-based compensation award. Forfeitures are accounted for as they occur. The fair value of restricted stock awards is determined based on the market value of the Company’s shares on the grant date and the compensation expense is recognized on a straight-line basis during the service period of the respective grant. Derivative Instruments In the course of normal operations, the Company occasionally enters into contracts such as forward priced physical contracts for the purchase of raw materials that qualify for and are designated as normal purchase or normal sale contracts. Such contracts are exempted from the fair value accounting requirements and are accounted for at the time product is purchased or sold under the related contract. The Company does not engage in speculative transactions, nor does the Company hold or issue financial instruments for trading purposes. Revenue Recognition We recognize revenues from sales of products when title and risk of ownership pass to the customer. Final sales prices are fixed and based on purchase orders. Sales allowances and customer incentives are treated as reductions to sales and are provided for based on historical experiences and current estimates. Sales of our products are moderately seasonal with the peak period being July - November of each year. In addition, the Company presents revenues net of sales tax and net of certain payments to our independent manufacturer representatives (“Representatives”). Representatives are national companies that are in the business of providing HVAC units and other related products and services to customers. The end user customer orders a bundled group of products and services from the Representative and expects the Representative to fulfill the order. Only after the specifications are agreed to by the Representative and the customer, and the decision is made to use an AAON HVAC unit, will we receive notice of the order. We establish the amount we must receive for our HVAC unit (“minimum sales price”), but do not control the total order price which is negotiated by the Representative with the end user customer. We are responsible for billings and collections resulting from all sales transactions, including those initiated by our Representatives. The Representatives submit the total order price to us for invoicing and collection. The total order price includes our minimum sales price and could contain an additional amount which may include both the Representatives’ fee and amounts due for additional products and services required by the customer. These additional products and services may include controls purchased from another manufacturer to operate the unit, start-up services, and curbs for supporting the unit (“Third Party Products”). All are associated with the purchase of a HVAC unit but may be provided by the Representative or another third party. The Company is under no obligation related to Third Party Products. The Representatives’ fee and Third Party Products amounts (“Due to Representatives”) are paid only after all amounts associated with the order are collected from the customer. The Due to Representatives amount is paid only after all amounts associated with the order are collected from the customer. The amount of payments to our representatives was $55.0 million, $55.4 million , and $59.7 million for each of the years ended December 31, 2016 , 2015 , and 2014 , respectively. The Company also sells extended warranties on parts for various lengths of time ranging from six months to 10 years. Revenue for these separately priced warranties is deferred and recognized on a straight-line basis over the separately priced warranty period. Insurance Reserves Under the Company’s insurance programs, coverage is obtained for significant liability limits as well as those risks required to be insured by law or contract. It is the policy of the Company to self-insure a portion of certain expected losses related primarily to workers’ compensation and medical liability. Provisions for losses expected under these programs are recorded based on the Company’s estimates of the aggregate liabilities for the claims incurred. Product Warranties A provision is made for the estimated cost of maintaining product warranties to customers at the time the product is sold based upon historical claims experience by product line. The Company records a liability and an expense for estimated future warranty claims based upon historical experience and management's estimate of the level of future claims. Changes in the estimated amounts recognized in prior years are recorded as an adjustment to the liability and expense in the current year. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Because these estimates and assumptions require significant judgment, actual results could differ from those estimates and could have a significant impact on our results of operations, financial position and cash flows. We reevaluate our estimates and assumptions as needed, but at a minimum on a quarterly basis. The most significant estimates include, but are not limited to, the allowance for doubtful accounts, inventory reserves, warranty accrual, workers compensation accrual, medical insurance accrual, share-based compensation and income taxes. Actual results could differ materially from those estimates.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Accounts Receivable	Accounts Receivable Accounts receivable and the related allowance for doubtful accounts are as follows: December 31, 2016 2015 (in thousands) Accounts receivable $ 43,091 $ 50,139 Less: Allowance for doubtful accounts (90 ) (115 ) Total, net $ 43,001 $ 50,024 Years Ending December 31, 2016 2015 2014 Allowance for doubtful accounts: (in thousands) Balance, beginning of period $ 115 $ 171 $ 193 Provisions for losses on accounts receivables, net of adjustments (25 ) (48 ) — Accounts receivable written off, net of recoveries — (8 ) (22 ) Balance, end of period $ 90 $ 115 $ 171

Inventories

Inventories	12 Months Ended
	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventories	Inventories The components of inventories and the related changes in the allowance for excess and obsolete inventories are as follows: December 31, 2016 2015 (in thousands) Raw materials $ 43,438 $ 33,853 Work in process 2,279 2,522 Finished goods 3,017 2,881 48,734 39,256 Less: Allowance for excess and obsolete inventories (1,382 ) (757 ) Total, net $ 47,352 $ 38,499 Years Ending December 31, 2016 2015 2014 Allowance for excess and obsolete inventories: (in thousands) Balance, beginning of period $ 757 $ 714 $ 579 Provisions for excess and obsolete inventories 625 178 135 Inventories written off — (135 ) — Balance, end of period $ 1,382 $ 757 $ 714

Note Receivable

Note Receivable	12 Months Ended
	Dec. 31, 2016
Note Receivable [Abstract]
Note Receivable	Note Receivable In connection with the closure of our Canadian facility on May 18, 2009, we sold land and a building in September 2010 and assumed a note receivable from the borrower secured by the property. The $1.1 million , 15 year note has an interest rate of 4.0% and is payable to us monthly, and has a $0.6 million balloon payment due in October 2025 . Interest payments are recognized in interest income. We evaluate the note for impairment on a quarterly basis. We determine the note receivable to be impaired if we are uncertain of its collectability based on the contractual terms. At December 31, 2016 and 2015 , there was no impairment.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Years Ending December 31, 2016 2015 2014 Supplemental disclosures: (in thousands) Interest paid $ — $ — $ — Income taxes paid, net 27,353 24,125 26,456 Non-cash investing and financing activities: Non-cash capital expenditures 270 83 (79 )

Warranties

Warranties	12 Months Ended
	Dec. 31, 2016
Guarantees [Abstract]
Warranties	Warranties The Company has warranties with various terms from 18 months for parts to 25 years for certain heat exchangers. The Company has an obligation to replace parts or service its products if conditions under the warranty are met. A provision is made for estimated warranty costs at the time the related products are sold based upon the warranty period, historical trends, new products and any known identifiable warranty issues. Changes in the warranty accrual are as follows: Years Ending December 31, 2016 2015 2014 Warranty accrual: (in thousands) Balance, beginning of period $ 8,469 $ 8,130 $ 7,352 Payments made (4,134 ) (3,978 ) (4,096 ) Provisions 3,601 4,317 4,874 Adjustments related to changes in estimates — — — Balance, end of period $ 7,936 $ 8,469 $ 8,130 Warranty expense: $ 3,601 $ 4,317 $ 4,874

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities At December 31, accrued liabilities were comprised of the following: December 31, 2016 2015 (in thousands) Warranty $ 7,936 $ 8,469 Due to representatives 9,907 10,597 Payroll 4,129 3,954 401(k) Contributions — 3,054 Profit sharing 1,967 2,220 Workers' compensation 580 366 Medical self-insurance 872 676 Customer prepayments 2,256 2,895 Donations 600 600 Employee benefits and other 3,693 4,404 Total $ 31,940 $ 37,235

Revolving Credit Facility

Revolving Credit Facility	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Revolving Credit Facility	Revolving Credit Facility Our revolving credit facility provides for maximum borrowings of $30.0 million which is provided by BOKF, NA dba Bank of Oklahoma, formerly known as Bank of Oklahoma, N.A. ("Bank of Oklahoma"). Under the line of credit, there was one standby letter of credit totaling $0.8 million as of December 31, 2016 . Borrowings available under the revolving credit facility at December 31, 2016 , were $29.2 million . Interest on borrowings is payable monthly at LIBOR plus 2.5% . No fees are associated with the unused portion of the committed amount. As of December 31, 2016 and 2015 , we had no balance outstanding under our revolving credit facility. At December 31, 2016 and 2015 , the weighted average interest rate was 3.0% and 2.6% , respectively. At December 31, 2016 , we were in compliance with our financial covenants. These covenants require that we meet certain parameters related to our tangible net worth and total liabilities to tangible net worth ratio. At December 31, 2016 our tangible net worth was $205.9 million , which meets the requirement of being at or above $125.0 million . Our total liabilities to tangible net worth ratio was 0.2 to 1.0, which meets the requirement of not being above 2 to 1. Effective July 25, 2016, the Company amended its revolving credit facility with the Bank of Oklahoma. The amendment extends the termination date of the revolving credit facility to July 27, 2018.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision (benefit) for income taxes consists of the following: Years Ending December 31, 2016 2015 2014 (in thousands) Current $ 25,790 $ 24,439 $ 26,199 Deferred 825 1,172 (2,111 ) Total $ 26,615 $ 25,611 $ 24,088 The provision for income taxes differs from the amount computed by applying the statutory federal income tax rate before the provision for income taxes. The reconciliation of the federal statutory income tax rate to the effective income tax rate is as follows: Years Ending December 31, 2016 2015 2014 Federal statutory rate 35 % 35 % 35 % State income taxes, net of federal benefit 5 % 5 % 5 % Domestic manufacturing deduction (3 )% (3 )% (4 )% Excess tax benefits (3 )% — % — % Other (1 )% (1 )% (1 )% 33 % 36 % 35 % As discussed in Note 11, the Company early adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, applying the changes for excess tax benefits and tax deficiencies prospectively. As a result, excess tax benefits and deficiencies are reported as an income tax benefit or expense on the statement of income rather than as a component of additional paid-in capital on the statement of equity. Excess tax benefits and deficiencies are treated as discrete items to the income tax provision in the reporting period in which they occur and are noted in the above table. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amount used for income tax purposes. The significant components of the Company’s deferred tax assets and liabilities are as follows: December 31, 2016 2015 (in thousands) Deferred income tax assets (liabilities): Accounts receivable and inventory reserves $ 587 $ 351 Warranty accrual 3,165 3,405 Other accruals 1,715 1,248 Share-based compensation 1,784 1,099 Donations 463 691 Other, net 738 986 Total deferred income tax assets 8,452 7,780 Property & equipment (17,983 ) (16,486 ) Total deferred income tax liabilities $ (17,983 ) $ (16,486 ) Net deferred income tax liabilities $ (9,531 ) $ (8,706 ) We file income tax returns in the U.S., state and foreign income tax returns jurisdictions. We are subject to U.S. examinations for tax years 2012 to present, and to non-U.S. income tax examinations for the tax years of 2012 to present. In addition, we are subject to state and local income tax examinations for the tax years 2012 to present. The Company continues to evaluate its need to file returns in various state jurisdictions. Any interest or penalties would be recognized as a component of income tax expense.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation On May 22, 2007, our stockholders adopted a Long-Term Incentive Plan (“LTIP”) which provided an additional 3.3 million shares that could be granted in the form of stock options, stock appreciation rights, restricted stock awards, performance units and performance awards, in addition to the shares from the previous plan, the 1992 Plan. Since inception of the LTIP, non-qualified stock options and restricted stock awards have been granted with the same vesting schedule as the 1992 Plan. Under the LTIP, the exercise price of shares granted may not be less than 100% of the fair market value at the date of the grant. On May 24, 2016, our stockholders adopted the 2016 Long-Term Incentive Plan ("2016 Plan") which provides for approximately 3.8 million shares, comprised of 3.4 million new shares provided for under the 2016 Plan and approximately 0.4 million shares that were available for issuance under the previous LTIP, that are now authorized for issuance under the 2016 Plan, that can be granted in the form of stock options, stock appreciation rights, restricted stock awards, performance awards, dividend equivalent rights, and other awards. Under the 2016 Plan, the exercise price of shares granted may not be less than 100% of the fair market value at the date of the grant. The 2016 Plan is administered by the Compensation Committee of the Board of Directors or such other committee of the Board of Directors as is designated by the Board of Directors (the “Committee”). Membership on the Committee is limited to independent directors. The Committee may delegate certain duties to one or more officers of the Company as provided in the 2016 Plan. The Committee determines the persons to whom awards are to be made, determines the type, size and terms of awards, interprets the 2016 Plan, establishes and revises rules and regulations relating to the 2016 Plan and makes any other determinations that it believes necessary for the administration of the 2016 Plan. The total pre-tax compensation cost related to unvested stock options not yet recognized as of December 31, 2016 is $8.5 million and is expected to be recognized over a weighted-average period of 2.61 years. The following weighted average assumptions were used to determine the fair value of the stock options granted on the original grant date for expense recognition purposes for options granted during December 31, 2016 , 2015 and 2014 using a Black Scholes-Merton Model: 2016 2015 2014 Director and Officers: Expected dividend yield $ 0.22 $ 0.18 N/A Expected volatility 41.19 % 44.14 % N/A Risk-free interest rate 2.00 % 1.97 % N/A Expected life (in years) 7.68 8.00 N/A Employees: Expected dividend yield $ 0.25 $ 0.22 $ 0.14 Expected volatility 34.50 % 42.71 % 44.85 % Risk-free interest rate 1.73 % 1.41 % 2.26 % Expected life (in years) 5.69 8.00 8.00 The expected term of the options is based on evaluations of historical and expected future employee exercise behavior. The risk-free interest rate is based on the U.S. Treasury rates at the date of grant with maturity dates approximately equal to the expected life at the grant date. Volatility is based on historical volatility of our stock over time periods equal to the expected life at grant date. The following is a summary of stock options vested and exercisable as of December 31, 2016 : Weighted Average Weighted Range of Number Remaining Average Exercise of Contractual Exercise Intrinsic Prices Shares Life Price Value (in thousands) $4.54 - 20.92 338,308 4.75 $ 8.03 $ 8,465 $20.96 - 26.50 71,928 8.56 22.50 759 Total 410,236 5.42 $ 10.57 $ 9,224 The following is a summary of stock options vested and exercisable as of December 31, 2015 : Weighted Average Weighted Range of Number Remaining Average Exercise of Contractual Exercise Intrinsic Prices Shares Life Price Value (in thousands) $4.31 - 8.65 421,237 4.89 $ 7.04 $ 6,814 $8.70 - 22.76 27,134 7.82 15.31 215 Total 448,371 5.07 $ 7.54 $ 7,029 The following is a summary of stock options vested and exercisable as of December 31, 2014 : Weighted Average Weighted Range of Number Remaining Average Exercise of Contractual Exercise Intrinsic Prices Shares Life Price Value (in thousands) $3.21 - 6.89 411,553 3.46 $ 5.16 $ 7,113 $7.13 - 8.17 81,050 6.54 7.27 1,226 $8.65 - 21.14 175,527 6.53 8.76 2,392 Total 668,130 4.64 $ 6.36 $ 10,731 A summary of option activity under the plans is as follows: Weighted Average Exercise Options Shares Price Outstanding at December 31, 2015 1,130,910 $ 13.38 Granted 651,546 29.94 Exercised (257,738 ) 8.00 Forfeited or Expired (74,014 ) 21.92 Outstanding at December 31, 2016 1,450,704 $ 21.33 Exercisable at December 31, 2016 410,236 $ 10.57 The total intrinsic value of options exercised during December 31, 2016 , 2015 and 2014 was $4.9 million , $7.4 million and $2.8 million , respectively. The cash received from options exercised during December 31, 2016 , 2015 and 2014 was $2.1 million , $2.8 million and $1.3 million , respectively. The impact of these cash receipts is included in financing activities in the accompanying Consolidated Statements of Cash Flows. Since 2007, as part of the LTIP and since May 2016 as part of the 2016 Plan, the Compensation Committee of the Board of Directors has authorized and issued restricted stock awards to directors and key employees. Restricted stock awards granted to directors vest one-third each year. All other restricted stock awards vest at a rate of 20% per year. The fair value of restricted stock awards is based on the fair market value of AAON common stock on the respective grant dates, reduced for the present value of dividends. These awards are recorded at their fair value on the date of grant and compensation cost is recorded using straight-line vesting over the service period. At December 31, 2016 , unrecognized compensation cost related to unvested restricted stock awards was approximately $6.5 million which is expected to be recognized over a weighted average period of 1.90 years. A summary of the unvested restricted stock awards is as follows: Weighted Average Grant date Restricted stock Shares Fair Value Unvested at December 31, 2015 410,023 $ 18.78 Granted 136,063 23.13 Vested (119,379 ) 17.81 Forfeited (18,545 ) 19.60 Unvested at December 31, 2016 408,162 $ 20.47 A summary of share-based compensation is as follows for the years ending December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Grant date fair value of awards during the period: (in thousands) Options $ 6,102 $ 3,685 $ 817 Restricted stock 3,147 2,985 5,024 Total $ 9,249 $ 6,670 $ 5,841 2016 2015 2014 Share-based compensation expense: (in thousands) Options $ 1,681 $ 833 $ 898 Restricted stock 2,676 2,058 1,280 Total $ 4,357 $ 2,891 $ 2,178 2016 2015 2014 Income tax benefit related to share-based compensation: (in thousands) Options $ 1,610 $ 2,165 $ 979 Restricted stock 458 280 260 Total $ 2,068 $ 2,445 $ 1,239 In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which makes several modifications to Topic 718 including: accounting for excess tax benefits and deficiencies; classifying excess tax benefits on the statement of cash flows; accounting for forfeitures; classifying awards that permit share repurchases to satisfy statutory tax-withholding requirement; and classifying tax payments on behalf of employees on the statement of cash flows. The ASU becomes effective for interim and annual reporting periods beginning after December 31, 2016. We early adopted the ASU effective July 1, 2016. The Company previously applied a forfeiture rate to its share-based compensation expense and adjusted expense to actual as awards vested and/or were forfeited. Upon adoption of ASU 2016-09, the Company accounts for forfeitures as they occur, rather than estimating forfeitures as of an award's grant date. This change in accounting policy election was adopted using a modified retrospective transition method and the Company recognized a cumulative-effect adjustment to retained earnings of approximately $ 150,000 . Tax payments made on behalf of an employee by repurchasing shares of stock are now shown separately as cash outflows from financing activities on the statement of cash flows. This provision was retrospectively adopted and prior period cash flows have been reclassified to conform with this presentation. Additionally, the Company retrospectively adopted the provision to classify excess tax benefits and deficiencies as cash flows from operating activities as part of cash payments for taxes on the statement of cash flows. Prior period cash flows have been reclassified to conform with this presentation.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	Employee Benefits Defined Contribution Plan - 401(k ) - We sponsor a defined contribution plan (the "Plan”). Eligible employees may make contributions in accordance with the Plan and IRS guidelines. In addition to the traditional 401(k), eligible employees are given the option of making an after-tax contribution to a Roth 401(k) or a combination of both. The Plan provides for automatic enrollment and for an automatic increase to the deferral percentage at January 1st of each year and each year thereafter. Eligible employees are automatically enrolled in the Plan at a 6% deferral rate and currently contributing employees deferral rates will be increased to 6% unless their current rate is above 6% or the employee elects to decline the automatic enrollment or increase. Effective October 1, 2013, the Plan was amended such that the Company contributed 3% of eligible payroll to the Plan for each employee and matched 100% up to 6% of employee contributions of eligible compensation. We contributed and continue to contribute in the form of cash and direct the investment to shares of AAON stock. Employees are 100% vested in salary deferral contributions and vest 20% per year at the end of years two through six of employment in employer matching contributions. The additional 3% Company contribution, a Safe-Harbor contribution, vested over two years. Effective January 1, 2016, the Plan was amended such that the Company matches 175% up to 6% of employee contributions of eligible compensation. The Company no longer contributes 3% of eligible payroll to the Plan for each employee. The Company ceased paying administrative expenses for the Plan at which time administrative expenses are paid for by Plan participants. Additionally, Plan participant forfeitures are used to reduce the cost of the Company contributions. For the years ended December 31, 2016 , 2015 and 2014 we made contributions of $5.9 million , $9.0 million and $6.8 million , respectively. Administrative expenses were approximately $40 thousand , $0.1 million , and $0.2 million for the years ended 2016 , 2015 and 2014 , respectively. Profit Sharing Bonus Plan - We maintain a discretionary profit sharing bonus plan under which approximately 10% of pre-tax profit is paid to eligible employees on a quarterly basis in order to reward employee productivity. Eligible employees are regular full-time employees who are actively employed and working on the first and last days of the calendar quarter and who were employed full-time for at least three full months prior to the beginning of the calendar quarter. Profit sharing expense was $9.0 million , $8.0 million and $7.8 million for the years ended December 31, 2016 , 2015 and 2014 , respectively.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Shareholders' Equity	Stockholders’ Equity Stock Repurchase - The Board has authorized three stock repurchase programs for the Company. The Company may purchase shares on the open market from time to time, up to a total of 5.7 million shares. The Board must authorize the timing and amount of these purchases. Effective May 24, 2016, the Board authorized up to $25.0 million in open market repurchases and on June 2, 2016, the Company executed a repurchase agreement in accordance with the rules and regulations of the SEC allowing the Company to repurchase an aggregate amount of $25.0 million or a total of approximately 2.0 million shares from the open market. The repurchase agreement will terminate upon the aforementioned thresholds having been met, on April 15, 2017, or upon other provisions contained in the repurchase agreement by either the Company or its agent. The Company also has a stock repurchase arrangement by which employee-participants in our 401(k) savings and investment plan are entitled to have shares in AAON, Inc. stock in their accounts sold to the Company. The maximum number of shares to be repurchased is contingent upon the number of shares sold by employee-participants. Lastly, the Company repurchases shares of AAON, Inc. stock from certain of its directors and employees for payment of statutory tax withholdings on stock transactions. A11 other repurchases from directors or employees are contingent upon Board approval. All repurchases are done at current market prices. Our repurchase activity is as follows: 2016 2015 2014 Program Shares Total $ $ per share Shares Total $ $ per share Shares Total $ $ per share Open market 165,598 $ 4,440,658 $ 26.82 1,037,590 $ 24,999,963 $ 24.09 1,016,717 $ 19,998,406 $ 19.67 401(k) 540,501 14,875,850 27.52 512,754 11,557,598 22.54 417,172 8,246,172 19.77 Directors and employees 30,072 823,446 27.38 25,746 585,413 22.74 54,341 1,038,459 19.11 Total 736,171 $ 20,139,954 $ 27.36 1,576,090 $ 37,142,974 $ 23.57 1,488,230 $ 29,283,037 $ 19.68 Inception to Date Program Shares Total $ $ per share Open market 3,834,819 $ 60,948,460 $ 15.89 401(k) 6,082,443 65,732,720 10.81 Directors and employees 1,873,632 15,663,608 8.36 Total 11,790,894 $ 142,344,788 $ 12.07 Dividends - At the discretion of the Board of Directors, we pay semi-annual cash dividends. Board approval is required to determine the date of declaration and amount for each semi-annual dividend payment. Our recent dividends are as follows: Declaration Date Record Date Payment Date Dividend per Share May 2, 2014 June 12, 2014 July 1, 2014 $0.09 November 4, 2014 December 2, 2014 December 23, 2014 $0.09 May 19, 2015 June 12, 2015 July 1, 2015 $0.11 October 29, 2015 December 2, 2015 December 23, 2015 $0.11 May 24, 2016 June 10, 2016 July 1, 2016 $0.11 November 9, 2016 December 2, 2016 December 23, 2016 $0.13 Additionally, on June 5, 2014, we declared a three-for-two stock split of the Company's common stock to be paid in the form of a stock dividend on July 16, 2014. Stockholders of record at the close of business on June 27, 2014 received one additional share for every two shares they held as of that date. We paid cash dividends of $12.7 million , $11.9 million and $9.7 million in 2016 , 2015 and 2014 , respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies We are subject to various claims and legal actions that arise in the ordinary course of business. We closely monitor these claims and legal actions and frequently consult with our legal counsel to determine whether they may, when resolved, have a material adverse effect on our financial position, results of operations or cash flows and we accrue and/or disclose loss contingencies as appropriate. We have concluded that the likelihood is remote that the ultimate resolution of any pending litigation or claims will be material or have a material adverse effect on the Company's business, financial position, results of operations or cash flows. We are occasionally party to short-term, cancellable and occasionally non-cancellable, fixed price contracts with major suppliers for the purchase of raw material and component parts. We expect to receive delivery of raw materials for use in our manufacturing operations. These contracts are not accounted for as derivative instruments because they meet the normal purchase and normal sales exemption.

New Accounting Pronouncements

New Accounting Pronouncements	12 Months Ended
	Dec. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements Changes to U.S. GAAP are established by the Financial Accounting Standards Board ("FASB") in the form of accounting standards updates ("ASUs") to the FASB's Accounting Standards Codification. We consider the applicability and impact of all ASUs. ASUs not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on our consolidated financial statements and notes thereto. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In August 2015, with the issuance of ASU 2015-14, the FASB amended the effective date for us to January 1, 2018. The following ASUs have been issued in 2016 along with ASU 2014-09 with the same effective dates and transition requirements: • ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which provides implementation guidance for Topic 606 on principal versus agent considerations. • ASU 2016-10, Identifying Performance Obligations and Licensing , which provides clarification for two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance. • ASU 2016-12, Revenue from Contracts with Customers , which further amends Topic 606. • ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers , which further amends Topic 606. The Company plans to adopt using the retrospective transition method. The Company has begun assessing the impact of ASU 2015-09 and believes the impact will not be material to the consolidated financial statements. We do not expect to complete our evaluation until after our first quarter of 2017. Once we adopt ASU 2014-09, we do not anticipate that our internal control framework will materially change, but rather that existing internal controls will be modified and augmented, as necessary, to consider our new revenue recognition policy effective January 1, 2018. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , which will address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. The ASU becomes effective in the annual reporting period beginning after December 31, 2017, including interim reporting periods. We do not expect ASU 2016-01 will have a material effect on our consolidated financial statements and notes thereto.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic net income per share is calculated by dividing net income by the weighted average number of shares of common stock outstanding during the period. Diluted net income per share assumes the conversion of all potentially dilutive securities and is calculated by dividing net income by the sum of the weighted average number of shares of common stock outstanding plus all potentially dilutive securities. Dilutive common shares consist primarily of stock options and restricted stock awards. ASU 2016-09 impacts the calculation of diluted weighted average shares under the treasury stock method as the Company no longer increases or decreases the assumed proceeds from an employee vesting in, or exercising, a share-based payment award by the amount of excess tax benefits or deficiencies taken to additional paid-in capital. The following table sets forth the computation of basic and diluted earnings per share: 2016 2015 2014 Numerator: (in thousands, except share and per share data) Net income $ 53,376 $ 45,728 $ 44,158 Denominator: Basic weighted average shares 52,924,398 54,045,841 54,809,319 Effect of dilutive stock options and restricted stock 525,356 435,643 559,697 Diluted weighted average shares 53,449,754 54,481,484 55,369,016 Earnings per share: Basic $ 1.01 $ 0.85 $ 0.81 Dilutive $ 1.00 $ 0.84 $ 0.80 Anti-dilutive shares: Shares 469,603 146,548 32,436

Quarterly Results (Unaudited)

Quarterly Results (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results (Unaudited)	Quarterly Results (Unaudited) The following is a summary of the quarterly results of operations for the years ending December 31, 2016 and 2015 : Quarter First Second Third Fourth (in thousands, except per share data) 2016 Net sales $ 85,422 $ 102,319 $ 104,568 $ 91,668 Gross profit 25,731 32,747 33,092 26,510 Net income 10,806 (1) 14,341 (1) 15,682 11,420 Earnings per share: Basic $ 0.20 (1) $ 0.27 (1) $ 0.30 $ 0.22 Diluted $ 0.20 (1) $ 0.27 (1) $ 0.29 $ 0.21 2015 Net sales $ 76,768 $ 90,275 $ 94,360 $ 97,229 Gross profit 21,798 27,117 30,185 29,581 Net income 8,399 11,130 13,251 12,948 Earnings per share: Basic $ 0.16 $ 0.21 $ 0.24 $ 0.24 Diluted $ 0.15 $ 0.20 $ 0.24 $ 0.24 (1) As discussed in Notes 10 and 11, the Company early adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, effective July 1, 2016. As a result, excess tax benefits and deficiencies are reported as an income tax benefit or expense on the statement of income rather than as a component of additional paid-in capital on the statement of equity. The ASU required the application of the modified retrospective transition method as of the beginning of the annual period in which the guidance was adopted. As a result, 2016 net income as reported above will be recast when we file our first and second quarters in 2017. Net income will increase by $0.8 million and $0.4 million , for the first and second quarters of 2016, respectively. Additionally, earnings per basic and diluted share will increase approximately $.01 and $.01 , respectively, for each of the three months ended March 31, 2016 and June 30, 2016, respectively, versus what was reported above.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation These financial statements are prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"). The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly liquid temporary investments with original maturity dates of three months or less to be cash equivalents. Cash and cash equivalents consist of bank deposits and highly liquid, interest-bearing money market funds. The Company's cash and cash equivalents are held in a few financial institutions in amounts that exceed the insurance limits of the Federal Deposit Insurance Corporation. However, management believes that the Company's counterparty risks are minimal based on the reputation and history of the institutions selected.
Investments	Investments Certificates of Deposit We held $5.5 million and $12.0 million in certificates of deposit at December 31, 2016 and December 31, 2015 , respectively. At December 31, 2016 , the certificates of deposit bear interest ranging from 0.55% to 0.90% per annum and have various maturities ranging from less than two months to approximately 7 months . Investments Held to Maturity At December 31, 2016 , our investments held to maturity were comprised of $14.1 million of corporate notes and bonds with various maturities ranging from less than one month to approximately 6 months . The investments have moderate risk with S&P ratings ranging from AA to BBB-. We record the amortized cost basis and accrued interest of the corporate notes and bonds in the Consolidated Balance Sheets. We record the interest and amortization of bond premium to interest income in the Consolidated Statements of Income. The following summarizes the amortized cost and estimated fair value of our investments held to maturity at December 31, 2016 and December 31, 2015 : Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Fair Value December 31, 2016: (in thousands) Current assets: Investments held to maturity $ 14,083 $ — $ (12 ) $ 14,071 Non current assets: Investments held to maturity — — — — Total $ 14,083 $ — $ (12 ) $ 14,071 December 31, 2015: Current assets: Investments held to maturity $ 12,444 $ — $ (16 ) $ 12,428 Non current assets: Investments held to maturity 5,039 — (17 ) 5,022 Total $ 17,483 $ — $ (33 ) $ 17,450 We evaluate these investments for other-than-temporary impairments on a quarterly basis. We do not believe there was an other-than-temporary impairment for our investments at December 31, 2016 or 2015 .
Accounts and Note Receivable	Accounts and Note Receivable Accounts and note receivable are stated at amounts due from customers, net of an allowance for doubtful accounts. We generally do not require that our customers provide collateral. The Company determines its allowance for doubtful accounts by considering a number of factors, including the credit risk of specific customers, the customer’s ability to pay current obligations, historical trends, economic and market conditions and the age of the receivable. Accounts are considered past due when the balance has been outstanding for ninety days past negotiated credit terms. Past due accounts are generally written-off against the allowance for doubtful accounts only after all collection attempts have been exhausted.
Concentration of Credit Risk	Concentration of Credit Risk Our customers are concentrated primarily in the domestic commercial and industrial new construction and replacement markets. To date, our sales have been primarily to the domestic market, with foreign sales accounting for approximately 4% , 4% and 6% of revenues for the years ended December 31, 2016 , 2015 and 2014 , respectively. One customer, Texas AirSystems, accounted for 10% or more of our sales during 2016 and 2015 . No customer accounted for 10% or more of our sales during 2014 . No customer accounted for 5% or more of our accounts receivable balance at December 31, 2016 or 2015 .
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, receivables, accounts payable and accrued liabilities approximate fair value because of the short-term maturity of the items. The carrying amount of the Company's revolving line of credit, and other payables, approximate their fair values either due to their short term nature, the variable rates associated with the debt or based on current rates offered to the Company for debt with similar characteristics.
Inventories	Inventories Inventories are valued at the lower of cost or market using the first-in, first-out (“FIFO”) method. Cost in inventory includes purchased parts and materials, direct labor and applied manufacturing overhead. We establish an allowance for excess and obsolete inventories based on product line changes, the feasibility of substituting parts and the need for supply and replacement parts.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment, including significant improvements, are recorded at cost, net of accumulated depreciation. Repairs and maintenance and any gains or losses on disposition are included in operations. Depreciation is computed using the straight-line method over the following estimated useful lives: Buildings 3-40 years Machinery and equipment 3-15 years Furniture and fixtures 3-7 years
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets We review long-lived assets for possible impairment when events or changes in circumstances indicate, in management’s judgment, that the carrying amount of an asset may not be recoverable. Recoverability is measured by a comparison of the carrying amount of an asset or asset group to its estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the undiscounted cash flows are less than the carrying amount of the asset or asset group, an impairment loss is recognized for the amount by which the carrying amount of the asset or asset group exceeds its fair value.
Research and Development	Research and Development The costs associated with research and development for the purpose of developing and improving new products are expensed as incurred. For the years ended December 31, 2016 , 2015 , and 2014 research and development costs amounted to approximately $12.0 million, $7.5 million , and $6.3 million , respectively.
Advertising	Advertising Advertising costs are expensed as incurred. Advertising expense for the years ended December 31, 2016 , 2015 , and 2014 was approximately $1.4 million, $1.2 million , and $1.0 million , respectively.
Shipping and Handling	Shipping and Handling We incur shipping and handling costs in the distribution of products sold that are recorded in cost of sales. Shipping charges that are billed to the customer are recorded in revenues and as an expense in cost of sales. For the years ended December 31, 2016 , 2015 and 2014 shipping and handling fees amounted to approximately $10.3 million, $9.6 million , and $8.5 million , respectively.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the book carrying amounts and the tax basis of assets and liabilities. We establish accruals for unrecognized tax positions when it is more likely than not that our tax return positions may not be fully sustained. The Company records a valuation allowance for deferred tax assets when, in the opinion of management, it is more likely than not that deferred tax assets will not be realized.
Share-Based Compensation	Share-Based Compensation The Company recognizes expense for its share-based compensation based on the fair value of the awards that are granted. The Company’s share-based compensation plans provide for the granting of stock options and restricted stock. The fair values of stock options are estimated at the date of grant using the Black-Scholes-Merton option valuation model. The use of the Black-Scholes-Merton option valuation model requires the input of subjective assumptions. Measured compensation cost is recognized ratably over the vesting period of the related share-based compensation award. Forfeitures are accounted for as they occur. The fair value of restricted stock awards is determined based on the market value of the Company’s shares on the grant date and the compensation expense is recognized on a straight-line basis during the service period of the respective grant.
Financial Derivatives	Derivative Instruments In the course of normal operations, the Company occasionally enters into contracts such as forward priced physical contracts for the purchase of raw materials that qualify for and are designated as normal purchase or normal sale contracts. Such contracts are exempted from the fair value accounting requirements and are accounted for at the time product is purchased or sold under the related contract. The Company does not engage in speculative transactions, nor does the Company hold or issue financial instruments for trading purposes.
Revenue Recognition	Revenue Recognition We recognize revenues from sales of products when title and risk of ownership pass to the customer. Final sales prices are fixed and based on purchase orders. Sales allowances and customer incentives are treated as reductions to sales and are provided for based on historical experiences and current estimates. Sales of our products are moderately seasonal with the peak period being July - November of each year. In addition, the Company presents revenues net of sales tax and net of certain payments to our independent manufacturer representatives (“Representatives”). Representatives are national companies that are in the business of providing HVAC units and other related products and services to customers. The end user customer orders a bundled group of products and services from the Representative and expects the Representative to fulfill the order. Only after the specifications are agreed to by the Representative and the customer, and the decision is made to use an AAON HVAC unit, will we receive notice of the order. We establish the amount we must receive for our HVAC unit (“minimum sales price”), but do not control the total order price which is negotiated by the Representative with the end user customer. We are responsible for billings and collections resulting from all sales transactions, including those initiated by our Representatives. The Representatives submit the total order price to us for invoicing and collection. The total order price includes our minimum sales price and could contain an additional amount which may include both the Representatives’ fee and amounts due for additional products and services required by the customer. These additional products and services may include controls purchased from another manufacturer to operate the unit, start-up services, and curbs for supporting the unit (“Third Party Products”). All are associated with the purchase of a HVAC unit but may be provided by the Representative or another third party. The Company is under no obligation related to Third Party Products. The Representatives’ fee and Third Party Products amounts (“Due to Representatives”) are paid only after all amounts associated with the order are collected from the customer. The Due to Representatives amount is paid only after all amounts associated with the order are collected from the customer. The amount of payments to our representatives was $55.0 million, $55.4 million , and $59.7 million for each of the years ended December 31, 2016 , 2015 , and 2014 , respectively. The Company also sells extended warranties on parts for various lengths of time ranging from six months to 10 years. Revenue for these separately priced warranties is deferred and recognized on a straight-line basis over the separately priced warranty period.
Insurance Reserves	Insurance Reserves Under the Company’s insurance programs, coverage is obtained for significant liability limits as well as those risks required to be insured by law or contract. It is the policy of the Company to self-insure a portion of certain expected losses related primarily to workers’ compensation and medical liability. Provisions for losses expected under these programs are recorded based on the Company’s estimates of the aggregate liabilities for the claims incurred.
Product Warranties	Product Warranties A provision is made for the estimated cost of maintaining product warranties to customers at the time the product is sold based upon historical claims experience by product line. The Company records a liability and an expense for estimated future warranty claims based upon historical experience and management's estimate of the level of future claims. Changes in the estimated amounts recognized in prior years are recorded as an adjustment to the liability and expense in the current year.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Because these estimates and assumptions require significant judgment, actual results could differ from those estimates and could have a significant impact on our results of operations, financial position and cash flows. We reevaluate our estimates and assumptions as needed, but at a minimum on a quarterly basis. The most significant estimates include, but are not limited to, the allowance for doubtful accounts, inventory reserves, warranty accrual, workers compensation accrual, medical insurance accrual, share-based compensation and income taxes. Actual results could differ materially from those estimates.
New Accounting Pronouncements	Changes to U.S. GAAP are established by the Financial Accounting Standards Board ("FASB") in the form of accounting standards updates ("ASUs") to the FASB's Accounting Standards Codification. We consider the applicability and impact of all ASUs. ASUs not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on our consolidated financial statements and notes thereto. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In August 2015, with the issuance of ASU 2015-14, the FASB amended the effective date for us to January 1, 2018. The following ASUs have been issued in 2016 along with ASU 2014-09 with the same effective dates and transition requirements: • ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which provides implementation guidance for Topic 606 on principal versus agent considerations. • ASU 2016-10, Identifying Performance Obligations and Licensing , which provides clarification for two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance. • ASU 2016-12, Revenue from Contracts with Customers , which further amends Topic 606. • ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers , which further amends Topic 606. The Company plans to adopt using the retrospective transition method. The Company has begun assessing the impact of ASU 2015-09 and believes the impact will not be material to the consolidated financial statements. We do not expect to complete our evaluation until after our first quarter of 2017. Once we adopt ASU 2014-09, we do not anticipate that our internal control framework will materially change, but rather that existing internal controls will be modified and augmented, as necessary, to consider our new revenue recognition policy effective January 1, 2018. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , which will address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. The ASU becomes effective in the annual reporting period beginning after December 31, 2017, including interim reporting periods. We do not expect ASU 2016-01 will have a material effect on our consolidated financial statements and notes thereto.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Amortized Cost and Estimated Fair Value of Investments Held to Maturity	The following summarizes the amortized cost and estimated fair value of our investments held to maturity at December 31, 2016 and December 31, 2015 : Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Fair Value December 31, 2016: (in thousands) Current assets: Investments held to maturity $ 14,083 $ — $ (12 ) $ 14,071 Non current assets: Investments held to maturity — — — — Total $ 14,083 $ — $ (12 ) $ 14,071 December 31, 2015: Current assets: Investments held to maturity $ 12,444 $ — $ (16 ) $ 12,428 Non current assets: Investments held to maturity 5,039 — (17 ) 5,022 Total $ 17,483 $ — $ (33 ) $ 17,450
Estimated Useful Lives	Depreciation is computed using the straight-line method over the following estimated useful lives: Buildings 3-40 years Machinery and equipment 3-15 years Furniture and fixtures 3-7 years

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Accounts Receivable	December 31, 2016 2015 (in thousands) Accounts receivable $ 43,091 $ 50,139 Less: Allowance for doubtful accounts (90 ) (115 ) Total, net $ 43,001 $ 50,024
Accounts Receivable (Allowance)	Years Ending December 31, 2016 2015 2014 Allowance for doubtful accounts: (in thousands) Balance, beginning of period $ 115 $ 171 $ 193 Provisions for losses on accounts receivables, net of adjustments (25 ) (48 ) — Accounts receivable written off, net of recoveries — (8 ) (22 ) Balance, end of period $ 90 $ 115 $ 171

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventories	December 31, 2016 2015 (in thousands) Raw materials $ 43,438 $ 33,853 Work in process 2,279 2,522 Finished goods 3,017 2,881 48,734 39,256 Less: Allowance for excess and obsolete inventories (1,382 ) (757 ) Total, net $ 47,352 $ 38,499
Inventories (Allowance)	Years Ending December 31, 2016 2015 2014 Allowance for excess and obsolete inventories: (in thousands) Balance, beginning of period $ 757 $ 714 $ 579 Provisions for excess and obsolete inventories 625 178 135 Inventories written off — (135 ) — Balance, end of period $ 1,382 $ 757 $ 714

Supplemental Cash Flow Inform29

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Years Ending December 31, 2016 2015 2014 Supplemental disclosures: (in thousands) Interest paid $ — $ — $ — Income taxes paid, net 27,353 24,125 26,456 Non-cash investing and financing activities: Non-cash capital expenditures 270 83 (79 )

Warranties (Tables)

Warranties (Tables)	12 Months Ended
	Dec. 31, 2016
Guarantees [Abstract]
Warranty	Changes in the warranty accrual are as follows: Years Ending December 31, 2016 2015 2014 Warranty accrual: (in thousands) Balance, beginning of period $ 8,469 $ 8,130 $ 7,352 Payments made (4,134 ) (3,978 ) (4,096 ) Provisions 3,601 4,317 4,874 Adjustments related to changes in estimates — — — Balance, end of period $ 7,936 $ 8,469 $ 8,130 Warranty expense: $ 3,601 $ 4,317 $ 4,874

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued Liabilities	At December 31, accrued liabilities were comprised of the following: December 31, 2016 2015 (in thousands) Warranty $ 7,936 $ 8,469 Due to representatives 9,907 10,597 Payroll 4,129 3,954 401(k) Contributions — 3,054 Profit sharing 1,967 2,220 Workers' compensation 580 366 Medical self-insurance 872 676 Customer prepayments 2,256 2,895 Donations 600 600 Employee benefits and other 3,693 4,404 Total $ 31,940 $ 37,235

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Provision for Income Taxes	The provision (benefit) for income taxes consists of the following: Years Ending December 31, 2016 2015 2014 (in thousands) Current $ 25,790 $ 24,439 $ 26,199 Deferred 825 1,172 (2,111 ) Total $ 26,615 $ 25,611 $ 24,088
Federal Statutory Income Tax Rate Reconciliation	The reconciliation of the federal statutory income tax rate to the effective income tax rate is as follows: Years Ending December 31, 2016 2015 2014 Federal statutory rate 35 % 35 % 35 % State income taxes, net of federal benefit 5 % 5 % 5 % Domestic manufacturing deduction (3 )% (3 )% (4 )% Excess tax benefits (3 )% — % — % Other (1 )% (1 )% (1 )% 33 % 36 % 35 %
Deferred Tax Assets and Liabilities	The significant components of the Company’s deferred tax assets and liabilities are as follows: December 31, 2016 2015 (in thousands) Deferred income tax assets (liabilities): Accounts receivable and inventory reserves $ 587 $ 351 Warranty accrual 3,165 3,405 Other accruals 1,715 1,248 Share-based compensation 1,784 1,099 Donations 463 691 Other, net 738 986 Total deferred income tax assets 8,452 7,780 Property & equipment (17,983 ) (16,486 ) Total deferred income tax liabilities $ (17,983 ) $ (16,486 ) Net deferred income tax liabilities $ (9,531 ) $ (8,706 )

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Assumptions	The following weighted average assumptions were used to determine the fair value of the stock options granted on the original grant date for expense recognition purposes for options granted during December 31, 2016 , 2015 and 2014 using a Black Scholes-Merton Model: 2016 2015 2014 Director and Officers: Expected dividend yield $ 0.22 $ 0.18 N/A Expected volatility 41.19 % 44.14 % N/A Risk-free interest rate 2.00 % 1.97 % N/A Expected life (in years) 7.68 8.00 N/A Employees: Expected dividend yield $ 0.25 $ 0.22 $ 0.14 Expected volatility 34.50 % 42.71 % 44.85 % Risk-free interest rate 1.73 % 1.41 % 2.26 % Expected life (in years) 5.69 8.00 8.00
Summary of Stock Options Outstanding	The following is a summary of stock options vested and exercisable as of December 31, 2016 : Weighted Average Weighted Range of Number Remaining Average Exercise of Contractual Exercise Intrinsic Prices Shares Life Price Value (in thousands) $4.54 - 20.92 338,308 4.75 $ 8.03 $ 8,465 $20.96 - 26.50 71,928 8.56 22.50 759 Total 410,236 5.42 $ 10.57 $ 9,224 The following is a summary of stock options vested and exercisable as of December 31, 2015 : Weighted Average Weighted Range of Number Remaining Average Exercise of Contractual Exercise Intrinsic Prices Shares Life Price Value (in thousands) $4.31 - 8.65 421,237 4.89 $ 7.04 $ 6,814 $8.70 - 22.76 27,134 7.82 15.31 215 Total 448,371 5.07 $ 7.54 $ 7,029 The following is a summary of stock options vested and exercisable as of December 31, 2014 : Weighted Average Weighted Range of Number Remaining Average Exercise of Contractual Exercise Intrinsic Prices Shares Life Price Value (in thousands) $3.21 - 6.89 411,553 3.46 $ 5.16 $ 7,113 $7.13 - 8.17 81,050 6.54 7.27 1,226 $8.65 - 21.14 175,527 6.53 8.76 2,392 Total 668,130 4.64 $ 6.36 $ 10,731
Summary of Stock Option Activity	A summary of option activity under the plans is as follows: Weighted Average Exercise Options Shares Price Outstanding at December 31, 2015 1,130,910 $ 13.38 Granted 651,546 29.94 Exercised (257,738 ) 8.00 Forfeited or Expired (74,014 ) 21.92 Outstanding at December 31, 2016 1,450,704 $ 21.33 Exercisable at December 31, 2016 410,236 $ 10.57
Summary of Unvested Restricted Stock Awards	A summary of the unvested restricted stock awards is as follows: Weighted Average Grant date Restricted stock Shares Fair Value Unvested at December 31, 2015 410,023 $ 18.78 Granted 136,063 23.13 Vested (119,379 ) 17.81 Forfeited (18,545 ) 19.60 Unvested at December 31, 2016 408,162 $ 20.47
Summary of Grant Date Fair Value of Awards During Period	2016 2015 2014 Grant date fair value of awards during the period: (in thousands) Options $ 6,102 $ 3,685 $ 817 Restricted stock 3,147 2,985 5,024 Total $ 9,249 $ 6,670 $ 5,841
Summary of Share-Based Compensation Expense	2016 2015 2014 Share-based compensation expense: (in thousands) Options $ 1,681 $ 833 $ 898 Restricted stock 2,676 2,058 1,280 Total $ 4,357 $ 2,891 $ 2,178
Summary of Income Tax Benefit Related to Share-Based Compensation	2016 2015 2014 Income tax benefit related to share-based compensation: (in thousands) Options $ 1,610 $ 2,165 $ 979 Restricted stock 458 280 260 Total $ 2,068 $ 2,445 $ 1,239

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Schedule of Share Repurchases	Our repurchase activity is as follows: 2016 2015 2014 Program Shares Total $ $ per share Shares Total $ $ per share Shares Total $ $ per share Open market 165,598 $ 4,440,658 $ 26.82 1,037,590 $ 24,999,963 $ 24.09 1,016,717 $ 19,998,406 $ 19.67 401(k) 540,501 14,875,850 27.52 512,754 11,557,598 22.54 417,172 8,246,172 19.77 Directors and employees 30,072 823,446 27.38 25,746 585,413 22.74 54,341 1,038,459 19.11 Total 736,171 $ 20,139,954 $ 27.36 1,576,090 $ 37,142,974 $ 23.57 1,488,230 $ 29,283,037 $ 19.68 Inception to Date Program Shares Total $ $ per share Open market 3,834,819 $ 60,948,460 $ 15.89 401(k) 6,082,443 65,732,720 10.81 Directors and employees 1,873,632 15,663,608 8.36 Total 11,790,894 $ 142,344,788 $ 12.07
Schedule of Dividends	Our recent dividends are as follows: Declaration Date Record Date Payment Date Dividend per Share May 2, 2014 June 12, 2014 July 1, 2014 $0.09 November 4, 2014 December 2, 2014 December 23, 2014 $0.09 May 19, 2015 June 12, 2015 July 1, 2015 $0.11 October 29, 2015 December 2, 2015 December 23, 2015 $0.11 May 24, 2016 June 10, 2016 July 1, 2016 $0.11 November 9, 2016 December 2, 2016 December 23, 2016 $0.13

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share Table	The following table sets forth the computation of basic and diluted earnings per share: 2016 2015 2014 Numerator: (in thousands, except share and per share data) Net income $ 53,376 $ 45,728 $ 44,158 Denominator: Basic weighted average shares 52,924,398 54,045,841 54,809,319 Effect of dilutive stock options and restricted stock 525,356 435,643 559,697 Diluted weighted average shares 53,449,754 54,481,484 55,369,016 Earnings per share: Basic $ 1.01 $ 0.85 $ 0.81 Dilutive $ 1.00 $ 0.84 $ 0.80 Anti-dilutive shares: Shares 469,603 146,548 32,436

Quarterly Results (Unaudited) (

Quarterly Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations	The following is a summary of the quarterly results of operations for the years ending December 31, 2016 and 2015 : Quarter First Second Third Fourth (in thousands, except per share data) 2016 Net sales $ 85,422 $ 102,319 $ 104,568 $ 91,668 Gross profit 25,731 32,747 33,092 26,510 Net income 10,806 (1) 14,341 (1) 15,682 11,420 Earnings per share: Basic $ 0.20 (1) $ 0.27 (1) $ 0.30 $ 0.22 Diluted $ 0.20 (1) $ 0.27 (1) $ 0.29 $ 0.21 2015 Net sales $ 76,768 $ 90,275 $ 94,360 $ 97,229 Gross profit 21,798 27,117 30,185 29,581 Net income 8,399 11,130 13,251 12,948 Earnings per share: Basic $ 0.16 $ 0.21 $ 0.24 $ 0.24 Diluted $ 0.15 $ 0.20 $ 0.24 $ 0.24 (1) As discussed in Notes 10 and 11, the Company early adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, effective July 1, 2016. As a result, excess tax benefits and deficiencies are reported as an income tax benefit or expense on the statement of income rather than as a component of additional paid-in capital on the statement of equity. The ASU required the application of the modified retrospective transition method as of the beginning of the annual period in which the guidance was adopted. As a result, 2016 net income as reported above will be recast when we file our first and second quarters in 2017. Net income will increase by $0.8 million and $0.4 million , for the first and second quarters of 2016, respectively. Additionally, earnings per basic and diluted share will increase approximately $.01 and $.01 , respectively, for each of the three months ended March 31, 2016 and June 30, 2016, respectively, versus what was reported above.

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)customer	Dec. 31, 2015USD ($)customer	Dec. 31, 2014USD ($)customer
Schedule of Accounting Policies [Line Items]
Investments in certificates of deposit	$ 5,500	$ 12,000
Certificates of deposit interest rate, lower range	0.55%
Certificates of deposit interest rate, upper range	0.90%
Investments held to maturity	$ 14,083	17,483
Research and development costs	12,000	7,500	$ 6,300
Advertising expense	1,400	1,200	1,000
Shipping and handling fees	10,300	9,600	8,500
Payments to representatives	$ 55,000	$ 55,400	$ 59,700
Extended product warranties, minimum length	6 months
Extended product warranties, maximum length	10 years
Foreign Sales Revenue, Net [Member]
Schedule of Accounting Policies [Line Items]
Concentration risk, percentage	4.00%	4.00%	6.00%
Sales Revenue, Net [Member]
Schedule of Accounting Policies [Line Items]
Number of major customers | customer	1	1	0
Accounting for More Than 5% of Accounts Receivable
Schedule of Accounting Policies [Line Items]
Number of major customers	0	0
Concentration risk, percentage	5.00%	5.00%
Minimum
Schedule of Accounting Policies [Line Items]
Certificates of deposit maturity dates	2 months
Investments maturity date	1 month
Maximum
Schedule of Accounting Policies [Line Items]
Certificates of deposit maturity dates	7 months
Investments maturity date	6 months

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Summary of Investments Held to Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 14,083	$ 17,483
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(12)	(33)
Fair Value	14,071	17,450
Held-to-maturity Securities, Noncurrent	0	5,039
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(12)	(16)
Fair Value	14,071	12,428
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	0	(17)
Fair Value	$ 0	$ 5,022

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2016
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Furniture and Fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Furniture and Fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Accounts receivable	$ 43,091	$ 50,139
Less: Allowance for doubtful accounts	(90)	(115)
Total, net	$ 43,001	$ 50,024

Accounts Receivable (Allowance)

Accounts Receivable (Allowance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts:
Balance, beginning of period	$ 115	$ 171	$ 193
Provisions for losses on accounts receivables, net of adjustments	(25)	(48)	0
Accounts receivable written off, net of recoveries	0	(8)	(22)
Balance, end of period	$ 90	$ 115	$ 171

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
Raw materials	$ 43,438	$ 33,853
Work in process	2,279	2,522
Finished goods	3,017	2,881
Inventory, gross	48,734	39,256
Less: Allowance for excess and obsolete inventories	(1,382)	(757)	$ (714)	$ (579)
Total, net	$ 47,352	$ 38,499

Inventories (Allowance) (Detail

Inventories (Allowance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for excess and obsolete inventories:
Balance, beginning of period	$ 757	$ 714	$ 579
Provisions for excess and obsolete inventories	625	178	135
Inventories written off	0	(135)	0
Balance, end of period	$ 1,382	$ 757	$ 714

Note Receivable (Details)

Note Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2010
Note Receivable [Abstract]
Note receivable	$ 657	$ 661	$ 1,100
Interest rate			4.00%
Balloon payment on note receivable			$ 600
Balloon payment due date	October 2,025

Supplemental Cash Flow Inform45

Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental disclosures:
Interest paid	$ 0	$ 0	$ 0
Income taxes paid, net	27,353	24,125	26,456
Non-cash investing and financing activities:
Non-cash capital expenditures	$ 270	$ 83	$ (79)

Warranties (Details)

Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Warranty accrual:
Balance, beginning of period	$ 8,469	$ 8,130	$ 7,352
Payments made	(4,134)	(3,978)	(4,096)
Provisions	3,601	4,317	4,874
Adjustments related to changes in estimates	0	0	0
Balance, end of period	7,936	8,469	8,130
Warranty expense	$ 3,601	$ 4,317	$ 4,874

Warranties (Details Narrative)

Warranties (Details Narrative)	12 Months Ended
	Dec. 31, 2016
Guarantees [Abstract]
Product warranty accrual, minimum length	18 months
Product warranty accrual, maximum length	25 years

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Warranty	$ 7,936	$ 8,469
Due to representatives	9,907	10,597
Payroll	4,129	3,954
Other Employee Related Liabilities, Current	0	3,054
Profit sharing	1,967	2,220
Workers' compensation	580	366
Medical self-insurance	872	676
Customer prepayments	2,256	2,895
Donations	600	600
Employee benefits and other	3,693	4,404
Total	$ 31,940	$ 37,235

Revolving Credit Facility (Deta

Revolving Credit Facility (Details)	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Line of Credit Facility [Line Items]
Actual net worth for compliance	$ 205,900,000
Minimum net worth required for compliance	$ 125,000,000
Ratio of total liability to net worth	0.2
Maximum ratio of total liability to net worth for compliance	2
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility maximum borrowings	$ 30,000,000
Standby letter of credit	800,000
Borrowings available under the revolving credit facility	$ 29,200,000
Frequency of periodic payments	monthly
Fees associated with unused portion of committed amount	$ 0
Borrowings outstanding under revolving credit facility	$ 0	$ 0
Weighted average interest rate	3.00%	2.60%
Revolving Credit Facility [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Stated percentage	2.50%

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Current	$ 25,790	$ 24,439	$ 26,199
Deferred	825	1,172	(2,111)
Total	$ 26,615	$ 25,611	$ 24,088

Income Taxes - Federal Statutor

Income Taxes - Federal Statutory Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	5.00%	5.00%	5.00%
Domestic manufacturing deduction	(3.00%)	(3.00%)	(4.00%)
Excess tax benefits	(3.00%)	0.00%	0.00%
Other	(1.00%)	(1.00%)	(1.00%)
Total	33.00%	36.00%	35.00%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Net long-term deferred assets and (liabilities) relating to:
Accounts receivable and inventory reserves	$ 587	$ 351
Warranty accrual	3,165	3,405
Other accruals	1,715	1,248
Share-based compensation	1,784	1,099
Donations	463	691
Other, net	738	986
Total deferred income tax assets	8,452	7,780
Property & equipment	(17,983)	(16,486)
Total deferred income tax liabilities	(17,983)	(16,486)
Net deferred income tax liabilities	$ 9,531	$ 8,706

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Assumptions (Details) - 2007 Long-Term Incentive Plan	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Director and Officers [Member]
Expected dividend yield	22.00%	18.00%
Expected volatility	41.19%	44.14%
Risk-free interest rate	2.00%	1.97%
Expected life (in years)	7 years 8 months 5 days	8 years
Employees
Expected dividend yield	25.00%	22.00%	14.00%
Expected volatility	34.50%	42.71%	44.85%
Risk-free interest rate	1.73%	1.41%	2.26%
Expected life (in years)	5 years 8 months 8 days	8 years	8 years

Share-Based Compensation - Su54

Share-Based Compensation - Summary of Stock Options Outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of shares vested and exercisable	410,236	448,371	668,130
Options vested and exercisable weighted average remaining contractual life	5 years 5 months	5 years 27 days	4 years 7 months 20 days
Options vested and exercisable weighted average exercise price	$ 10.57	$ 7.54	$ 6.36
Options vested and exercisable intrinsic value	$ 9,224	$ 7,029	$ 10,731
4.54-20.92
Range of exercise prices, lower range	$ 4.54
Range of exercise prices, upper range	$ 20.92
Number of shares vested and exercisable	338,308
Options vested and exercisable weighted average remaining contractual life	4 years 9 months
Options vested and exercisable weighted average exercise price	$ 8.03
Options vested and exercisable intrinsic value	$ 8,465
20.96-26.50
Range of exercise prices, lower range	$ 20.96
Range of exercise prices, upper range	$ 26.50
Number of shares vested and exercisable	71,928
Options vested and exercisable weighted average remaining contractual life	8 years 6 months 22 days
Options vested and exercisable weighted average exercise price	$ 22.50
Options vested and exercisable intrinsic value	$ 759
4.31-8.65
Range of exercise prices, lower range		$ 4.31
Range of exercise prices, upper range		$ 8.65
Number of shares vested and exercisable		421,237
Options vested and exercisable weighted average remaining contractual life		4 years 10 months 20 days
Options vested and exercisable weighted average exercise price		$ 7.04
Options vested and exercisable intrinsic value		$ 6,814
8.70-22.76
Range of exercise prices, lower range		$ 8.70
Range of exercise prices, upper range		$ 22.76
Number of shares vested and exercisable		27,134
Options vested and exercisable weighted average remaining contractual life		7 years 9 months 25 days
Options vested and exercisable weighted average exercise price		$ 15.31
Options vested and exercisable intrinsic value		$ 215
3.21-6.89
Range of exercise prices, lower range			$ 3.21
Range of exercise prices, upper range			$ 6.89
Number of shares vested and exercisable			411,553
Options vested and exercisable weighted average remaining contractual life			3 years 5 months 15 days
Options vested and exercisable weighted average exercise price			$ 5.16
Options vested and exercisable intrinsic value			$ 7,113
7.13-8.17
Range of exercise prices, lower range			$ 7.13
Range of exercise prices, upper range			$ 8.17
Number of shares vested and exercisable			81,050
Options vested and exercisable weighted average remaining contractual life			6 years 6 months 15 days
Options vested and exercisable weighted average exercise price			$ 7.27
Options vested and exercisable intrinsic value			$ 1,226
8.65-21.14
Range of exercise prices, lower range			$ 8.65
Range of exercise prices, upper range			$ 21.14
Number of shares vested and exercisable			175,527
Options vested and exercisable weighted average remaining contractual life			6 years 6 months 12 days
Options vested and exercisable weighted average exercise price			$ 8.76
Options vested and exercisable intrinsic value			$ 2,392

Share-Based Compensation - Su55

Share-Based Compensation - Summary of Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Shares
Outstanding, beginning of period (in shares) | shares	1,130,910
Granted (in shares) | shares	651,546
Exercised (in shares) | shares	(257,738)
Forfeited or Expired (in shares) | shares	(74,014)
Outstanding, end of period (in shares) | shares	1,450,704
Exercisable, end of period (in shares) | shares	410,236
Weighted Average Exercise Price
Outstanding, beginning of period (weighted average exercise price) | $ / shares	$ 13.38
Granted (weighted average exercise price) | $ / shares	29.94
Exercised (weighted average exercise price) | $ / shares	8
Forfeited or Expired (weighted average exercise price) | $ / shares	21.92
Outstanding, end of period (weighted average exercise price) | $ / shares	21.33
Exercisable, end of period (weighted average exercise price) | $ / shares	$ 10.57

Share-Based Compensation - Su56

Share-Based Compensation - Summary of Unvested Restricted Stock Awards (Details)	12 Months Ended
	Dec. 31, 2016$ / sharesshares
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) | shares	410,023
Granted (in shares) | shares	136,063
Vested (in shares) | shares	(119,379)
Forfeited (in shares) | shares	(18,545)
Unvested, end of period (in shares) | shares	408,162
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Unvested, beginning of period (weighted average grant date fair value) | $ / shares	$ 18.78
Granted (weighted average grant date fair value) | $ / shares	23.13
Vested (weighted average grant date fair value) | $ / shares	17.81
Forfeited (weighted average grant date fair value) | $ / shares	19.60
Unvested, end of period (weighted average grant date fair value) | $ / shares	$ 20.47

Share-Based Compensation - Su57

Share-Based Compensation - Summary of Grant Date Fair Value of Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options	$ 6,102	$ 3,685	$ 817
Restricted stock	3,147	2,985	5,024
Total	$ 9,249	$ 6,670	$ 5,841

Share-Based Compensation - Su58

Share-Based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options	$ 1,681	$ 833	$ 898
Restricted stock	2,676	2,058	1,280
Total	$ 4,357	$ 2,891	$ 2,178

Share-Based Compensation - Su59

Share-Based Compensation - Summary of Income Tax Benefit Related to Share-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options	$ 1,610	$ 2,165	$ 979
Restricted stock	458	280	260
Total	$ 2,068	$ 2,445	$ 1,239

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($) $ in Thousands	May 24, 2016	May 22, 2007	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock authorized to be issued under plan (in shares)	3,800,000
Unrecognized pre-tax compensation cost			$ 8,500
Weighted average recognition period (in years)			2 years 7 months 10 days
Total intrinsic value of options exercised during period			$ 4,900	$ 7,400	$ 2,800
Cash received from options exercised during period			2,100	2,800	$ 1,300
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-09 | Retained Earnings
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative effect of new accounting principle in period of adoption				$ 150
2007 Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock authorized to be issued under plan (in shares)	400,000	3,300,000
Exercise price of shares granted may not be less than fair market value (percentage)		100.00%
2007 Long-Term Incentive Plan | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized pre-tax compensation cost			$ 6,500
Weighted average recognition period (in years)			1 year 10 months 25 days
Annual vesting, percentage			20.00%
2016 Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock authorized to be issued under plan (in shares)	3,400,000
Exercise price of shares granted may not be less than fair market value (percentage)	100.00%

Employee Benefits - Narrative (

Employee Benefits - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Definedcontributionemployeeautomaticcontributionpercentag	6.00%
Company 401K plan contribution (percentage)	3.00%
Employer matching contribution, percent of match	100.00%
Maximum annual contributions per employee, percent	6.00%
Employee salary deferral contributions percentage vested	100.00%
Employer contribution annual vesting percentage	20.00%
Employer matching contributions	$ 5,900	$ 9,000	$ 6,800
Administrative expenses	$ 40	100	200
Profits sharing, percent of pre-tax profit paid to eligible employees on quarterly basis	10.00%
Profit sharing expense	$ 9,000	$ 8,000	$ 7,800
Effective January 1, 2016 [Member]
Defined Benefit Plan Disclosure [Line Items]
Company 401K plan contribution (percentage)	3.00%
Employer matching contribution, percent of match	175.00%
Maximum annual contributions per employee, percent	6.00%
Over Two Years
Defined Benefit Plan Disclosure [Line Items]
Company 401K plan contribution (percentage)	3.00%

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details)	Nov. 09, 2016$ / shares	May 24, 2016USD ($)$ / shares	Oct. 29, 2015$ / shares	May 19, 2015$ / sharesshares	Nov. 04, 2014$ / shares	Jul. 16, 2014	May 02, 2014$ / shares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Jun. 02, 2016USD ($)shares
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares) | shares								736,171	1,576,090	1,488,230			11,790,894
Aggregate price of shares repurchased since inception | $								$ 20,139,954	$ 37,142,974	$ 29,283,037			$ 142,344,788
Average price of shares repurchased since inception (per share) | $ / shares								$ 27.36	$ 23.57	$ 19.68			$ 12.07
Dividends declared (per share) | $ / shares								$ 0.24	$ 0.22	$ 0.18
Stock split, conversion ratio						1.5
Cash dividends paid | $								$ 12,700,000	$ 11,900,000	$ 9,700,000
Regular Semi-Annual Dividend
Schedule of Shareholders' Equity [Line Items]
Dividends declared (per share) | $ / shares	$ 0.13	$ 0.11	$ 0.11	$ 0.11	$ 0.09		$ 0.09
2010 Stock Repurchase Program [Member]
Schedule of Shareholders' Equity [Line Items]
Stock repurchase program amount authorized (in shares) | shares				5,700,000										2,000,000
Stock repurchase program amount authorized, value | $		$ 25,000,000												$ 25,000,000
Stock repurchased during period (in shares) | shares								165,598	1,037,590	1,016,717	3,834,819
Aggregate price of shares repurchased since inception | $								$ 4,440,658	$ 24,999,963	$ 19,998,406	$ 60,948,460
Average price of shares repurchased since inception (per share) | $ / shares								$ 26.82	$ 24.09	$ 19.67	$ 15.89
2005 401(k) Stock Repurchase Program [Member]
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares) | shares								540,501	512,754	417,172			6,082,443
Aggregate price of shares repurchased since inception | $								$ 14,875,850	$ 11,557,598	$ 8,246,172			$ 65,732,720
Average price of shares repurchased since inception (per share) | $ / shares								$ 27.52	$ 22.54	$ 19.77			$ 10.81
2006 Director and Officer Repurchase Program [Member]
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares) | shares								30,072	25,746	54,341		1,873,632
Aggregate price of shares repurchased since inception | $								$ 823,446	$ 585,413	$ 1,038,459		$ 15,663,608
Average price of shares repurchased since inception (per share) | $ / shares								$ 27.38	$ 22.74	$ 19.11		$ 8.36

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 11,420	$ 15,682	$ 14,341	$ 10,806	$ 12,948	$ 13,251	$ 11,130	$ 8,399	$ 53,376	$ 45,728	$ 44,158
Basic weighted average shares									52,924,398	54,045,841	54,809,319
Effect of dilutive stock options and restricted stock									525,356	435,643	559,697
Diluted weighted average shares									53,449,754	54,481,484	55,369,016
Basic (usd per share)	$ 0.22	$ 0.30	$ 0.27	$ 0.20	$ 0.24	$ 0.24	$ 0.21	$ 0.16	$ 1.01	$ 0.85	$ 0.81
Diluted (usd per share)	$ 0.21	$ 0.29	$ 0.27	$ 0.20	$ 0.24	$ 0.24	$ 0.20	$ 0.15	$ 1	$ 0.84	$ 0.80
Anti-dilutive shares (in shares)									469,603	146,548	32,436

Quarterly Results (Unaudited)64

Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 91,668	$ 104,568	$ 102,319	$ 85,422	$ 97,229	$ 94,360	$ 90,275	$ 76,768	$ 383,977	$ 358,632	$ 356,322
Gross profit	26,510	33,092	32,747	25,731	29,581	30,185	27,117	21,798	118,080	108,681	108,263
Net income	$ 11,420	$ 15,682	$ 14,341	$ 10,806	$ 12,948	$ 13,251	$ 11,130	$ 8,399	$ 53,376	$ 45,728	$ 44,158
Earnings per share:
Basic (usd per share)	$ 0.22	$ 0.30	$ 0.27	$ 0.20	$ 0.24	$ 0.24	$ 0.21	$ 0.16	$ 1.01	$ 0.85	$ 0.81
Diluted (usd per share)	$ 0.21	$ 0.29	$ 0.27	$ 0.20	$ 0.24	$ 0.24	$ 0.20	$ 0.15	$ 1	$ 0.84	$ 0.80
Accounting Standards Update 2016-09, Statutory Tax Withholding Component [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income			$ 400	$ 800
Earnings per share:
Basic (usd per share)			$ 0.01	$ 0.01
Diluted (usd per share)			$ 0.01	$ 0.01