Gentex (GNTX) 10-K 23 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 02, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Entity Registrant Name	GENTEX CORP
Entity Central Index Key	355811
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		295,281,110
Entity Public Float			$4,135,375,784
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$497,429,804	$309,591,724
Accounts receivable	168,008,704	143,046,590
Inventories	141,757,884	120,074,164
Prepaid expenses and other	49,441,302	28,473,764
Total current assets	856,637,694	601,186,242
PLANT AND EQUIPMENT:
Land, buildings and improvements	231,160,686	223,191,567
Machinery and equipment	554,425,200	507,768,233
Construction-in-process	56,685,789	41,481,572
Total Plant and Equipment	842,271,675	772,441,372
Less- Accumulated depreciation	-468,880,683	-415,420,147
Net Plant and Equipment	373,390,992	357,021,225
OTHER ASSETS:
Goodwill	307,365,845	307,365,845
Long-term investments	114,642,567	107,005,522
Intangible Assets, net	346,875,000	366,175,000
Patents and other assets, net	23,627,931	25,334,600
Total other assets	792,511,343	805,880,967
TOTAL ASSETS	2,022,540,029	1,764,088,434
CURRENT LIABILITIES:
Accounts payable	71,456,983	56,510,321
Accrued liabilities:
Salaries, wages and vacation	8,984,609	7,770,868
Income taxes	768,142	13,316,102
Royalties	12,051,121	9,374,449
Dividends declared	23,619,837	20,380,923
Current portion of long term debt	7,500,000	7,500,000
Other	9,050,471	5,127,751
Total current liabilities	133,431,163	119,980,414
LONG TERM DEBT	258,125,000	265,625,000
DEFERRED INCOME TAXES	59,571,421	50,879,337
TOTAL LIABILITIES	451,127,584	436,484,751
SHAREHOLDERS’ INVESTMENT:
Preferred stock, no par value, 5,000,000 shares authorized; none issued or outstanding	0	0
Common stock, par value $.06 per share; 400,000,000 shares authorized; 295,247,958 and 291,156,046 shares issued and outstanding in 2014 and 2013 respectively.	17,714,877	17,469,362
Additional paid-in capital	553,836,483	470,131,097
Retained earnings	988,548,070	818,027,861
Accumulated other comprehensive income:
Unrealized gain on investments	10,868,322	19,467,441
Unrealized gain (loss) on derivatives	-959,206	0
Cumulative translation adjustment	1,403,899	2,507,922
Total shareholders’ investment	1,571,412,445	1,327,603,683
TOTAL LIABILITES AND SHAREHOLDERS' INVESTMENT	$2,022,540,029	$1,764,088,434

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$0	$0
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$0.06	$0.06
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	295,247,958	291,156,046
Common stock, shares outstanding (in shares)	295,247,958	291,156,046

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
NET SALES	$1,375,501,159	$1,171,864,171	$1,099,559,521
COST OF GOODS SOLD	836,611,464	741,131,269	726,740,962
Gross profit	538,889,695	430,732,902	372,818,559
OPERATING EXPENSES:
Engineering, research and development	84,175,738	76,495,051	85,003,602
Selling, general and administrative	55,879,783	49,496,038	48,359,725
Litigation Settlement	0	0	5,000,000
Total operating expenses	140,055,521	125,991,089	138,363,327
Income from operations	398,834,174	304,741,813	234,455,232
OTHER INCOME:
Investment income	6,016,727	6,724,717	5,307,180
Other, net	10,475,589	16,597,513	9,863,188
Total other income	16,492,316	23,322,230	15,170,368
Income before provision for income taxes	415,326,490	328,064,043	249,625,600
PROVISION FOR INCOME TAXES	126,721,911	105,134,094	81,038,760
NET INCOME	$288,604,579	$222,929,949	$168,586,840
EARNINGS PER SHARE:
Basic (in dollars per share)	$0.99	$0.78	$0.59
Diluted (in dollars per share)	$0.98	$0.77	$0.59
Cash Dividends Declared per Share (in dollars per share)	$0.31	$0.28	$0.26

Consolidated_Statement_of_Comp

Consolidated Statement of Comprehensive Income (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income	$288,604,579	$222,929,949	$168,586,840
Other comprehensive income (loss) before tax:
Foreign currency translation adjustments	-1,104,023	48,989	328,976
Unrealized gains (losses) on derivatives	-1,475,702	0	0
Unrealized gains (losses) on available-for sales securities, net	-13,229,414	6,701,020	7,230,048
Other comprehensive income (loss), before tax	-15,809,139	6,750,009	7,559,024
Provision for income taxes related to components of other comprehensive income	-5,146,791	2,345,357	2,530,516
Other comprehensive Income (loss), net of tax	-10,662,348	4,404,652	5,028,508
Comprehensive Income	$277,942,231	$227,334,601	$173,615,348

Consolidated_Statement_of_Shar

Consolidated Statement of Shareholders' Investment (USD $)	3 Months Ended				12 Months Ended
	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		291,156,046			291,156,046
Beginning balance		$1,327,603,683		$1,120,960,556	$1,327,603,683	$1,120,960,556	$1,027,118,521
Issuance of common stock and the tax benefit of stock plan transactions					65,471,344	42,822,635	12,208,881
Repurchases of common stock					-30,010,882		-33,716,725
Stock-based compensation expense related to stock options, employee stock purchases and restricted stock					21,276,991	17,427,233	16,433,837
Dividends declared ($.26, $.28, and $.31 per share for the years ended December 31, 2012, 2013 and 2014 respectively)					-90,870,922	-80,941,342	-74,699,306
Net Income	70,975,000	68,566,000	69,881,000	45,431,000	288,604,579	222,929,949	168,586,840
Other comprehensive income					-10,662,348	4,404,652	5,028,508
Ending balance (in shares)	295,247,958		291,156,046		295,247,958	291,156,046
Ending balance	1,571,412,445		1,327,603,683		1,571,412,445	1,327,603,683	1,120,960,556
Common Stocks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		291,156,046		286,152,714	291,156,046	286,152,714	288,139,126
Beginning balance		17,469,362		17,169,162	17,469,362	17,169,162	17,288,348
Issuance of common stock and the tax benefit of stock plan transactions (in shares)					5,889,392	5,003,332	1,957,246
Issuance of common stock and the tax benefit of stock plan transactions					353,362	300,200	117,434
Repurchases of common stock (in shares)					-1,797,480		-3,943,658
Repurchases of common stock					-107,847		-236,620
Ending balance (in shares)	295,247,958		291,156,046		295,247,958	291,156,046	286,152,714
Ending balance	17,714,877		17,469,362		17,714,877	17,469,362	17,169,162
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		470,131,097		410,181,429	470,131,097	410,181,429	386,585,717
Issuance of common stock and the tax benefit of stock plan transactions					65,117,982	42,522,435	12,091,447
Repurchases of common stock					-2,689,587		-4,929,572
Stock-based compensation expense related to stock options, employee stock purchases and restricted stock					21,276,991	17,427,233	16,433,837
Ending balance	553,836,483		470,131,097		553,836,483	470,131,097	410,181,429
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		818,027,861		676,039,254	818,027,861	676,039,254	610,702,253
Repurchases of common stock					-27,213,448		-28,550,533
Dividends declared ($.26, $.28, and $.31 per share for the years ended December 31, 2012, 2013 and 2014 respectively)					-90,870,922	-80,941,342	-74,699,306
Net Income					288,604,579	222,929,949	168,586,840
Ending balance	988,548,070		818,027,861		988,548,070	818,027,861	676,039,254
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		21,975,363		17,570,711	21,975,363	17,570,711	12,542,203
Other comprehensive income					-10,662,348	4,404,652	5,028,508
Ending balance	$11,313,015		$21,975,363		$11,313,015	$21,975,363	$17,570,711

Consolidated_Statement_of_Shar1

Consolidated Statement of Shareholders' Investment (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Dividends declared per share (in dollars per share)	$0.31	$0.28	$0.26

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income	$288,604,579	$222,929,949	$168,586,840
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	77,376,305	62,854,155	50,179,823
Gain on disposal of assets	-44,410	-54,520	-419,382
Loss on disposal of assets	640,918	2,162,610	952,190
Gain on sale of investments	-16,742,536	-19,012,429	-9,584,288
Loss on sale of investments	1,149,627	882,918	1,216,027
Deferred income taxes	14,817,959	-7,726,800	843,484
Stock based compensation expense related to employee stock options, employee stock purchases and restricted stock	21,276,991	17,427,233	16,433,837
Excess tax benefits from stock based compensation	-5,502,339	-4,445,064	-815,651
Change in operating assets and liabilities:
Accounts receivable	-24,962,114	-22,347,450	810,022
Inventories	-21,683,721	39,856,102	28,823,046
Prepaid expenses and other	-21,946,622	-2,374,913	14,868,742
Accounts payable	14,946,662	13,310,319	-22,270,571
Accrued liabilities	-708,190	13,876,720	8,221,935
Net cash provided by operating activities	327,223,109	317,338,830	257,846,054
Activity in available-for-sale securities:
Sales proceeds	75,613,807	82,862,644	38,831,234
Maturities and calls	0	98,142,408	75,652,000
Purchases	-80,887,357	-60,543,153	-112,545,415
Plant and equipment additions	-72,518,987	-55,380,457	-117,474,449
Proceeds from sale of plant and equipment	223,833	386,399	1,064,614
Acquisition of businesses, net of cash acquired	0	-698,150,900	0
Increase in other assets	-2,144,779	-573,560	-17,602,228
Net cash (used for) investing activities	-79,713,483	-633,256,619	-132,074,244
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings on Credit Agreement	0	275,000,000	0
Repayment of long-term debt	-7,500,000	-1,875,000	0
Deferred financing costs	0	-956,441	0
Issuance of common stock from stock plan transactions	59,969,006	38,377,571	12,208,881
Cash dividends paid	-87,632,009	-79,160,345	-73,387,727
Repurchases of common stock	-30,010,882	0	-33,716,725
Excess tax benefits from stock based compensation	5,502,339	4,445,064	815,651
Net cash provided by (used for) financing activities	-59,671,546	235,830,849	-94,079,920
NET INCREASE IN CASH AND CASH EQUIVALENTS	187,838,080	-80,086,940	31,691,890
CASH AND CASH EQUIVALENTS, Beginning of year	309,591,724	389,678,664	357,986,774
CASH AND CASH EQUIVALENTS, End of year	$497,429,804	$309,591,724	$389,678,664

Summary_of_Significant_Account

Summary of Significant Accounting and Reporting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary Of Significant Accounting And Reporting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES
	The Company
	Gentex Corporation designs and manufactures automatic-dimming rearview mirrors and electronics for the automotive industry, dimmable aircraft windows for the aviation industry, and commercial smoke alarms and signaling devices for the fire protection industry. The Company’s largest business segment involves designing, developing, manufacturing and marketing interior and exterior automatic dimming automotive rearview mirrors and various electronic modules. The Company ships its product to all of the major automotive producing regions worldwide, which it supports with numerous sales, engineering and distribution locations worldwide.
	A substantial portion of the Company’s net sales and accounts receivable result from transactions with domestic and foreign automotive manufacturers and Tier 1 suppliers. The Company’s fire protection products are primarily sold to domestic distributors and original equipment manufacturers of fire and security systems. Aircraft windows are sold for use by aircraft manufacturers and a tier 1 supplier. The Company does not require collateral or other security for trade accounts receivable.
	Significant accounting policies of the Company not described elsewhere are as follows:
	Consolidation
	The consolidated financial statements include the accounts of Gentex Corporation and all of its wholly-owned subsidiaries (together the “Company”). All significant intercompany accounts and transactions have been eliminated.
	Cash Equivalents
	Cash equivalents consist of funds invested in bank accounts and money market funds that have daily liquidity.
	Allowance For Doubtful Accounts
	The Company bases its allowances for doubtful accounts related to receivables on historical credit and collections experience, and the specific identification of other potential problems, including the economic climate. Actual collections can differ, requiring adjustments to the allowances. Individual accounts receivable balances are evaluated on a monthly basis, and those balances considered uncollectible are charged to the allowance. Collections of amounts previously written off are recorded as an increase to the allowance.
	The following table presents the activity in the Company’s allowance for doubtful accounts:
		Beginning		Net			Deductions				Ending
		Balance		Additions/			and Other				Balance
				(Reductions)			Adjustments
				to Costs and
				Expenses
	Year Ended December 31, 2014:
	Allowance for Doubtful Accounts	$	3,202,388	$	(300,000	)	$	(191,140	)		$	2,711,248
	Year Ended December 31, 2013:
	Allowance for Doubtful Accounts	$	3,400,000	$	—		$	(197,612	)		$	3,202,388
	Year Ended December 31, 2012:
	Allowance for Doubtful Accounts	$	3,400,000	$	(577	)	577*				$	3,400,000
	*Represents excess recoveries and other adjustments over accounts written off.
	The Company’s overall allowance for doubtful accounts primarily relates to financially distressed Tier 1 automotive customers. The Company continues to work with these financially distressed customers in collecting past due balances.
	Investments
	The Company follows the provisions of ASC 820, “Fair Value Measurements and Disclosures” for its financial assets and liabilities, and for its non-financial assets and liabilities subject to fair value measurements. ASC 820 provides a framework for measuring the fair value of assets and liabilities. This framework is intended to provide increased consistency in how fair value determinations are made under various existing accounting standards that permit, or in some cases, require estimates of fair-market value. This standard also expanded financial statement disclosure requirements about a company’s use of fair-value measurements, including the effect of such measure on earnings. The cost of securities sold is based on the specific identification method.
	The Company’s investment securities (common stocks and mutual funds) are classified as available for sale and are stated at fair value based on quoted market prices, and as such are classified as Level 1 assets.
	Assets or liabilities that have recurring fair value measurements are shown below as of December 31, 2014 and December 31, 2013:
				Fair Value Measurements at Reporting Date Using
		Total as of		Quoted Prices in			Significant Other				Significant
				Active Markets			Observable				Unobservable
				for Identical			Inputs				Inputs
				Assets
	Description	31-Dec-14		(Level I)			(Level 2)				(Level 3)
	Cash & Cash Equivalents	$	497,429,804	$	497,429,804		$	—			$	—
	Short-Term Investments:
	Other	1,021		1,021
	Long-Term Investments:
	Corporate Bonds	—
	Common Stocks	24,648,451		24,648,451			—				—
	Mutual Funds – Equity	89,994,116		89,994,116			—				—
	Total	$	612,073,392	$	612,073,392		$	—			$	—
				Fair Value Measurements at Reporting Date Using
		Total as of		Quoted Prices in			Significant Other				Significant
				Active Markets			Observable				Unobservable
				for Identical			Inputs				Inputs
				Assets
	Description	December 31, 2013		(Level I)			(Level 2)				(Level 3)
	Cash & Cash Equivalents	$	309,591,724	$	309,591,724		$	—			$	—
	Long-Term Investments:
	Common Stocks	33,282,439		33,282,439			—				—
	Mutual Funds – Equity	73,723,083		73,723,083			—				—
	Total	$	416,597,246	$	416,597,246		$	—			$	—
	The amortized cost, unrealized gains and losses, and market value of investment securities are shown as of December 31, 2014 and 2013:
		Unrealized
	2014	Cost		Gains			Losses				Market Value
	Short-Term Investments:
	Other	1,021									1,021
	Long-Term Investments:
	Common Stocks	17,069,742		7,933,717			(355,008		)		24,648,451
	Mutual Funds-Equity	80,852,329		9,922,204			(780,417		)		89,994,116
	Total	$	97,923,092	$	17,855,921		$	(1,135,425	)		$	114,643,588
		Unrealized
2013	Cost		Gains			Losses			Market Value
Long-Term Investments:									—
Common Stocks	22,799,035		10,532,007			(48,603	)		33,282,439
Mutual Funds-Equity	54,256,577		19,466,506			—			73,723,083
Total	$	77,055,612	$	29,998,513		(48,603	)		$	107,005,522
Unrealized losses on investments as of December 31, 2014 are as follows:
	Aggregate Unrealized Losses		Aggregate Fair Value
Less than one year	$	1,135,425	$	19,972,258
Unrealized losses on investments as of December 31, 2013 are as follows:
	Aggregate Unrealized Losses		Aggregate Fair Value
Less than one year	$	48,603	$	1,886,080
ASC 320, “Accounting for Certain Investments in Debt and Equity Securities,” as amended and interpreted, provides guidance on determining when an investment is other-than-temporarily impaired. The Company reviews its fixed income and equity investment portfolio for any unrealized losses that would be deemed other-than-temporary and require the recognition of an impairment loss in income. If the cost of an investment exceeds its fair value, the Company evaluates, among other factors, general market conditions, the duration and extent to which the fair value is less than cost, and the Company’s intent and ability to hold the investments. Management also considers the type of security, related-industry and sector performance, as well as published investments ratings and analyst reports, to evaluate its portfolio. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded and new cost basis in the investment is established. If market, industry, and/or investee conditions deteriorate, the Company may incur future impairments. No investments were considered to be other-than-temporary impaired in 2014 and 2013.
Fair Value of Financial Instruments
The Company’s financial instruments consist of cash and cash equivalents, investments, accounts receivable accounts payable, short and long term debt. The Company’s estimate of the fair values of these financial instruments approximates their carrying amounts at December 31, 2014 and 2013.
Inventories
Inventories include material, direct labor and manufacturing overhead and are valued at the lower of first-in, first-out (FIFO) cost or market. Inventories consisted of the following as of December 31, 2014 and 2013:
	2014		2013
Raw materials	$	90,780,320	$	75,081,810
Work-in-process	24,135,944		21,409,976
Finished goods	26,841,620		23,582,378
Total Inventory	$	141,757,884	$	120,074,164
Allowances for slow-moving and obsolete inventories (which are included in the above inventory values) were $6.7 million and $6.9 million at December 31, 2014 and 2013. The year-over-year decrease in the allowance was primarily the result of write-offs of previously reserved inventory.
Plant and Equipment
Plant and equipment are stated at cost. Depreciation and amortization are computed for financial reporting purposes using the straight-line method, with estimated useful lives of 7 to 30 years for buildings and improvements, and 3 to 10 years for machinery and equipment. Depreciation expense was approximately $55.3 million, $55.0 million and $48.5 million in 2014, 2013 and 2012, respectively.
Impairment or Disposal of Long-Lived Assets
The Company reviews long-lived assets, including property, plant and equipment and other intangible assets with definite lives, for impairment whenever events or changes in circumstances indicate that the asset’s carrying amount may not be recoverable. The Company conducts its long-lived asset impairment analysis in accordance with ASC 360-10-15, “Impairment or Disposal of Long-Lived Assets.” ASC 360-10-15 requires the Company to group assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities and evaluate the asset group against the sum of the undiscounted future cash flows. If the undiscounted cash flows do not indicate the carrying amount of the asset is recoverable, an impairment charge is measured as the amount by which the carrying amount of the asset group exceeds its fair value based on discounted cash flow analysis or appraisals.
Patents
The Company’s policy is to capitalize costs incurred to obtain patents. The cost of patents is amortized over their useful lives. The cost of patents in process is not amortized until issuance. The Company periodically obtains intellectual property rights, in the ordinary course of business, and the cost of the rights are amortized over their useful lives.
Goodwill and Intangible Assets
Goodwill reflects the cost of an acquisition in excess of the fair values assigned to identifiable net assets acquired. The Company reviews goodwill for impairment during the fourth quarter on an annual basis or more frequently if events or changes in circumstances indicate that goodwill might be impaired. The Company performs an impairment review for its automotive reporting unit, which has been determined to be one of the Company’s reportable segments using a fair value method which incorporates management’s judgments and assumptions and may incorporate third party valuations. The fair value of a reporting unit refers to the price that would be received to sell the unit as a whole in an orderly transaction between market participants at the measurement date. In estimating the fair value, the Company uses a combination of widely accepted valuation methodologies incorporating certain judgments and assumptions to arrive at the fair value of the reporting unit.
The assumptions included in the impairment tests require judgment, and changes to these inputs could impact the results of the calculations which could result in an impairment charge in future periods if the carrying amount of the reporting unit exceeds its calculated fair value. Other than management's internal projections of future cash flows, the primary assumptions used in the impairment tests were the weighted-average cost of capital and long-term growth rates. Although the Company's cash flow forecasts are based on assumptions that are considered reasonable by management and consistent with the plans and estimates management is using to operate the underlying business, there are significant judgments in determining the expected future cash flows attributable to a reporting unit. There have been no impairment charges booked currently or in prior periods in which goodwill existed.
Indefinite lived intangible assets are also subject to annual impairment testing or more frequently if indicators of impairment are identified. Management judgment and assumptions are required in determining the underlying fair value of the indefinite lived intangible assets. While the Company believes the judgments and assumptions used in determining fair value are reasonable and no impairment existed at December 31, 2014 or December 31, 2013, different assumptions could change the estimated fair values and, therefore, impairment charges could be required, which could be material to the consolidated financial statements. The indefinite lived intangible assets were not impaired as a result of the annual test prepared by management for either period presented.
Revenue Recognition
The Company’s revenue is generated from sales of its products. Sales are recognized when the product is shipped and legal title has passed to the customer. The Company does not generate sales from arrangements with multiple deliverables.
In May 2014 the Financial Accounting Standards Board (FASB) issued the Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606), that will supersede nearly all existing revenue recognition guidance under US GAAP. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The standard will be effective for public entities for annual and interim periods beginning after December 15, 2016.
Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach. Entities electing the full retrospective adoption will apply the standard to each period presented in the financial statements. This means that entities will have to apply the new guidance as if it had been in effect since the inception of all its contracts with customers presented in the financial statements. Entities that elect the modified retrospective approach will apply the guidance retrospectively only to the most current period presented in the financial statements. This means that entities will have to recognize the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings at the date of initial application. The new revenue standard will be applied to contracts that are in progress at the date of initial application.
The Company is currently evaluating which adoption method it plans to use and is assessing the potential effect the new standard will have on its consolidated financial statements.
Advertising and Promotional Materials
All advertising and promotional costs are expensed as incurred and amounted to approximately $1.1 million, $0.4 million and $1.0 million, in 2014, 2013 and 2012, respectively.
Repairs and Maintenance
Major renewals and improvements of property and equipment are capitalized, and repairs and maintenance are expensed as incurred. The Company incurred expenses relating to the repair and maintenance of plant and equipment of approximately $17.9 million, $14.9 million and $13.8 million, in 2014, 2013 and 2012, respectively.
Self-Insurance
The Company is self-insured for a portion of its risk on workers’ compensation and employee medical costs. The arrangements provide for stop loss insurance to manage the Company’s risk. Operations are charged with the cost of claims reported and an estimate of claims incurred but not reported based upon historical claims lag information and other data.
Product Warranty
The Company periodically incurs product warranty costs. Any liabilities associated with product warranty are estimated based on known facts and circumstances and are not significant at December 31, 2014, 2013 and 2012. The Company does not offer extended warranties on its products.
Income Taxes
The provision for income taxes is based on the earnings reported in the consolidated financial statements. Deferred income tax assets and liabilities are computed for differences between the financial statement and tax basis of assets and liabilities that will result in taxable or deductible amounts in the future. Such deferred income tax asset and liability computations are based on enacted tax laws and rates.
Earnings Per Share
The following table reconciles the numerators and denominators used in the calculations of basic and diluted earnings per share (EPS) for each of the last three years adjusted for the 2 for 1 common stock split effected in the form of a 100% stock dividend issued on December 31, 2014:
	2014		2013			2012
Numerators:
Numerator for both basic and diluted EPS, net income	$	288,604,579	$	222,929,949		$	168,586,840
Denominators:
Denominator for basic EPS, weighted-average common shares outstanding	290,952,123		286,920,036			286,195,060
Potentially dilutive shares resulting from stock option plans	3,347,236		1,628,306			1,741,002
Denominator for diluted EPS	294,299,359		288,548,342			287,936,062
For the years ended December 31, 2014, 2013 and 2012, 1,228,694, 6,754,622 and 6,665,438 shares, respectively, related to stock option plans were not included in diluted average common shares outstanding because they were anti-dilutive.
Other Comprehensive Income (Loss)
Comprehensive income reflects the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. For the Company, comprehensive income represents net income adjusted for unrealized gains and losses on certain investments, unrealized gains and losses on certain derivative financial instruments and foreign currency translation adjustments and is further detailed in Note 9 to the Consolidated Financial Statements.
Foreign Currency Translation
The financial position and results of operations of the Company’s foreign subsidiaries are measured using the local currency as the functional currency. Assets and liabilities are translated at the exchange rate in effect at year-end. Income statement accounts are translated at the average rate of exchange in effect during the year. The resulting translation adjustment is recorded as a separate component of shareholders’ investment. Gains and losses arising from re-measuring foreign currency transactions into the appropriate currency are included in the determination of net income.
Derivative Financial Instruments
The Company accounts for derivative financial instruments in accordance with the guidance provided in ASC Topic 815, Derivatives and Hedging. The guidance requires that all derivative instruments be recognized as assets or liabilities on the consolidated balance sheets and measured at fair value. For derivatives designated as cash flow hedges, fair value changes in the effective portion of the hedging instrument are recognized in accumulated other comprehensive income on the consolidated balance sheets until the forecasted transaction affects earnings of the consolidated entity. Any ineffective portion of the fair value change is recognized in earnings immediately. At December 31, 2014, there was no ineffectiveness.
The Company seeks to reduce exposure to interest rate fluctuations through the use of an interest rate swap agreement. The Company does not buy and sell such financial instruments for investment or speculative purposes. The Company is exposed to credit loss in the event of nonperformance by the counterparties on derivative contracts. It is the Company’s practice to manage its credit risk on these transactions by dealing highly rated financial institutions.
Stock-Based Compensation Plans
The Company accounts for stock-based compensation using the fair value recognition provisions of ASC 718, “Compensation - Stock Compensation.” As described more fully in Note 5, the Company provides compensation benefits under two stock option plans, a restricted stock plan and an employee stock purchase plan.
Estimates
The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
New Accounting Standards
In May 2014 the Financial Accounting Standards Board (FASB) issued the Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606), that will supersede nearly all existing revenue recognition guidance under US GAAP. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The standard will be effective for public entities for annual and interim periods beginning after December 15, 2016.
Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach. Entities electing the full retrospective adoption will apply the standard to each period presented in the financial statements. This means that entities will have to apply the new guidance as if it had been in effect since the inception of all its contracts with customers presented in the financial statements. Entities that elect the modified retrospective approach will apply the guidance retrospectively only to the most current period presented in the financial statements. This means that entities will have to recognize the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings at the date of initial application. The new revenue standard will be applied to contracts that are in progress at the date of initial application.
The Company is currently evaluating which adoption method it plans to use and is assessing the potential effect the new standard will have on its consolidated financial statements.

Debt_and_Financing_Arrangement

Debt and Financing Arrangements	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Debt and Financing Arrangements	DEBT AND FINANCING ARRANGEMENTS
	On September 27, 2013, the Company entered into a Credit Agreement (the “Credit Agreement”) with certain banks and agents.
	Pursuant to the Credit Agreement, the Company is borrower under a $150 million senior revolving credit facility ("Revolver") and a $150 million term loan facility ("Term Loan"). Under the terms of the Credit Agreement, the Company is entitled, to further request an additional aggregate principal amount of up to $75 million, subject to the satisfaction of certain conditions. In addition, the Company is entitled to the benefit of swing loans from amounts otherwise available under the Revolver in the aggregate principal amount of up to $20 million and to request Letters of Credit from amounts otherwise available under the Revolver in the aggregate principal amount of up to $20 million, both subject to certain conditions. The obligations of the Company under the Credit agreement are not secured, but are subject to certain covenants. The Revolver expires and the Term Loan matures on September 27, 2018.
	During the years ended December 31, 2014 and 2013, the Company made principal repayments of $7.5 million and $1.9 million respectively, plus accrued interest, on the Term Loan, and accrued interest on the Revolver. The Company used cash and cash equivalents to fund the payments. As of December 31, 2014, $125 million was outstanding under the Revolver had the Company had availability of $25 million on the Revolver. Under current terms of the Term Loan, the Company will make principal repayments of $7.5 million annually through the maturity date of the Term Loan. As of December 31, 2014, $140.6 million was outstanding under the Term Loan.
	As of December 31, 2014, the borrowing rate on both its Term Loan and Revolver are derived from the one month LIBOR, and based on the Company's leverage ratio as of December 31, 2014, the interest rate on its borrowings is equal to 1.17%. Interest expense for the years ended December 31, 2014 and 2013 are netted within the "Other, net" section of the Consolidated Statements of Income and were $3.5 million and $0.9 million, respectively.
	The Credit Agreement contains customary representations and warranties and certain covenants that place certain limitations on the Company.
	As of December 31, 2014, the Company was in compliance with its covenants under the Credit Agreement.
	Interest Rate Swap
	On October 1, 2014, the Company entered into an interest rate swap transaction with a bank (the “Counterparty”). The Counterparty is among the syndicate of lenders under the existing Credit Agreement entered into on September 27, 2013. The Company entered into the interest rate swap transaction to mitigate the Company’s floating rate interest risk on an aggregate of $150 million of the Company’s debt that is currently outstanding under the Credit Agreement. The interest rate swap has an effective date of July 31, 2015 and a termination date of September 27, 2018 (which is the expiration date of the Credit Agreement). The Company is required to make certain monthly fixed rate payments to the Counterparty calculated on a notional amount of $150 million for the rate swap, while the Counterparty is obligated to make monthly floating rate payments to the Company referencing the same notional amount. The interest rate swap transaction has the effect of fixing the annual interest rate payable on $150 million of the Company’s outstanding debt under its existing credit facility to 1.89%, as of the effective date. The notional amounts of the interest rate swap agreement are used to measure interest to be paid or received and do not represent the amount of exposure to credit loss. This derivative instrument has been designated as a cash flow hedge of the variable interest payments on the related debt.
	Notwithstanding the terms of the interest rate swap transaction, the Company is ultimately obligated for all amounts due and payable under its existing Credit Agreement.
	The notional amount of the Company's derivative instruments are as follows:
		31-Dec-14		31-Dec-13		31-Dec-12
	Interest Rate swap	$	150,000,000	$	—	$	—
	The following table sets forth financial assets and liabilities measured at fair value in the consolidated balance sheets and the respective pricing levels to which the fair value measurements are classified within the fair value hierarchy. The Company uses the market approach to derive the value of its level 2 fair value measurements. Interest rate swaps are valued using publicized swap curves.
	Fair Value Measurements
	Quoted Prices with Other Observable Inputs (Level 2)
		31-Dec-14		31-Dec-13		31-Dec-12
	Financial assets:
	Interest Rate Swap Asset	$	—	$	—	$	—
	Financial Liabilities:
	Interest Rate Swap Liability (Other Accrued Liabilities)	$	1,475,702	$	—	$	—
	Based on loan balances as of December 31, 2014 and the effective date of July 31, 2015 of the interest rate swap, a one percent increase in the Company's borrowing rate would increase net interest expense paid by the Company on its borrowings by approximately $2.5 million dollars on an annual basis.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	The Company follows the provisions of the Financial Accounting Standards Codification 740 (“ASC 740”), “Income Taxes.” A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
		2014				2013				2012
	Beginning of year	$	7,351,000			$	4,168,000			$	2,476,000
	Additions based on tax positions related to the current year	1,328,000				1,595,000				785,000
	Additions for tax positions in prior years	634,000				1,633,000				907,000
	Reductions for tax positions in prior years	(676,000		)		(45,000		)		—
	Reductions as a result of a lapse of the applicable statute of limitations	(349,000		)		—				—
	End of year	$	8,288,000			$	7,351,000			$	4,168,000
	If recognized, unrecognized tax benefits would affect the effective tax rate.
	The Company recognizes interest and penalties related to unrecognized tax benefits through the provision for income taxes. The Company has accrued approximately $821,000 and $555,000 for interest as of December 31, 2014 and 2013, respectively. Interest recorded during 2014, 2013 and 2012 was not considered significant.
	The Company is also subject to periodic and routine audits in both domestic and foreign tax jurisdictions, and it is reasonably possible that the amounts of unrecognized tax benefits could change as a result of an audit.
	Based on the current audits in process, the payment of taxes as a result of audit settlements and the completion of tax examinations the Company does not expect these to have a material impact on the Company’s financial position or results of operations.
	For the majority of tax jurisdictions, the Company is no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations by tax authorities for years before 2010.
	In December 2014, the 2014 Tax Increase Prevention Act (TIPA) was signed into law and reinstated retroactively to January 1, 2014 various tax provisions known as tax "extenders" that had expired as of December 31, 2013. In accordance with ASC 740-45-15, the effects of changes in tax rates and laws on deferred tax balances and tax rates are recognized in the period the new legislation is enacted. As a result, the impact of the new legislation is reflected in the Company's consolidated financial position and results of operations in the fourth quarter of 2014.
	The provision for income taxes is based on the earnings reported in the accompanying consolidated financial statements. The Company recognizes deferred income tax liabilities and assets for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Under this method, deferred income tax liabilities and assets are determined based on the cumulative temporary differences between the financial statement and tax bases of assets and liabilities using enacted tax rates. Deferred income tax expense is measured by the net change in deferred income tax assets and liabilities during the year.
	The foreign components of income before the provision for income taxes were not material as of December 31, 2014, 2013 and 2012. The components of the provision for income taxes are as follows:
		2014				2013				2012
	Currently payable:
	Federal	$	108,689,911			$	95,285,094			$	76,507,760
	State	2,236,000				3,259,000				2,450,000
	Foreign	978,000				1,353,000				1,238,000
	Total	111,903,911				99,897,094				80,195,760
	Net deferred:
	Primarily federal	14,818,000				5,237,000				843,000
	Provision for income taxes	$	126,721,911			$	105,134,094			$	81,038,760
	The currently payable provision is further reduced by the tax benefits associated with the exercise, vesting or disposition of stock under the stock plans described in Note 5. These reductions totaled approximately $10.8 million, $7.4 million and $1.5 million in 2014, 2013 and 2012, respectively, and were recognized as an adjustment of additional paid-in capital.
	The effective income tax rates are different from the statutory federal income tax rates for the following reasons:
		2014			2013			2012
	Statutory federal income tax rate	35	%		35	%		35	%
	State income taxes, net of federal income tax benefit	0.3			0.6			0.6
	Domestic production exclusion	(2.60	)		(3.1	)		(2.9	)
	Research tax credit (1)	(2.00	)		(0.4	)		—
	Other	(0.20	)		(0.1	)		(0.2	)
	Effective income tax rate	30.5	%		32	%		32.5	%
	1) - Research tax credits applied in 2014 related to prior tax year amended tax filings were approximately 1.3 percentage points of the 2 percentage point reduction in the effective income tax rate.
	The tax effect of temporary differences which give rise to deferred income tax assets and liabilities at December 31, 2014 and 2013, are as follows:
		2014								2013
		Current				Non-Current				Current			Non-Current
	Assets:
	Accruals not currently deductible	$	2,605,711			$	224,803			$	2,970,671		$	182,803
	Stock based compensation	13,508,845				2,508,304				13,290,429			2,202,940
	Impairment loss on available-for-sale securities	—				135,724				—			175,091
	Intangible Assets	—				—				—			169,913
	Other	4,440,407				19,765				4,713,241			40,203
	Total deferred income tax assets	20,554,963				2,888,596				20,974,341			2,770,950
	Liabilities:
	Excess tax over book depreciation	—				(46,017,949		)		—			(41,374,851		)
	Goodwill	—				(8,868,168		)		—			(1,792,968		)
	Unrealized gain on investments	—				(6,368,670		)		—			(10,482,468		)
	Intangible assets	—				(1,205,230		)		—			—
	Other	(1,117,956		)						(558,249		)
	Net deferred income taxes	$	19,437,007			$	(59,571,421	)		$	20,416,092		$	(50,879,337	)
	Income taxes paid in cash were approximately $128.8 million, $97.1 million and $63.4 million in 2014, 2013 and 2012, respectively.
	No provision has been made for U.S. Federal and State income taxes on foreign taxes that may result from remittances of undistributed earnings of foreign subsidiaries as of December 31, 2014, 2013 and 2012. The Company expects such earnings will remain reinvested in those foreign subsidiaries indefinitely. Undistributed foreign earnings were not material as of December 31, 2014, 2013 and 2012.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plan	EMPLOYEE BENEFIT PLAN
	The Company has a 401(k) retirement savings plan in which substantially all of its employees may participate. The plan includes a provision for the Company to match a percentage of the employee’s contributions at a rate determined by the Company’s Board of Directors. In 2014, 2013 and 2012 the Company’s contributions were approximately $5.1 million, $2.8 million and $2.5 million, respectively. The increase in the Company's matching contributions in 2014 were due to changes, approved by the Company's Board of Directors, to the rate of Company match as well as increased participation in the plan.
	The Company does not provide health care benefits to retired employees.

StockBased_Compensation_Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	STOCK-BASED COMPENSATION PLANS
	At December 31, 2014, the Company had four equity incentive plans which include two stock option plans, a restricted stock plan and an employee stock purchase plan. All of the plans and any material amendments thereto have previously been approved by shareholders. On December 5, 2014, the Company announced that its Board of Directors approved a two-for-one split of our outstanding shares of common stock to be effected in the form of a 100% stock dividend. On December 31, 2014, shareholders of record at the close of business on December 17, 2014, were issued one additional share of common stock for each share owned by such shareholder.
	Employee Stock Option Plan
	In May 2014, the Employee Stock Option Plan was approved by shareholders, amending and restating a prior plan. The Company may grant up to 24,000,000 shares of common stock under the plan. The purpose of the plan is to provide an opportunity to use stock options as a means of recruiting new managerial and technical personnel and as a means for retaining certain employees of the Company and allow them to purchase shares of common stock of the Corporation and thereby have an additional incentive to contribute to the prosperity of the Company.
	The Company has granted options on 5,255,536 shares (net of shares from canceled/expired options) under the new plan through December 31, 2014. Under the plans, the option exercise price equals the stock’s market price on date of grant. The options vest after one to five years, and expire after five to seven years.
	The fair value of each option grant in the Employee Stock Option Plan was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the indicated periods:
		2014				2013				2012
	Dividend yield (1)	2.3		%		2.6		%		2.7		%
	Expected volatility (2)	38.5		%		44.7		%		45.5		%
	Risk-free interest rate (3)	1.7		%		1.3		%		0.8		%
	Expected term of options (in years) (4)	4.2				4				4.1
	Weighted-average grant-date fair value	$	4			$	4			$	3
	(1)    Represents the Company's estimated cash dividend yield over the expected term of option grant.
	-2	Amount is determined based on analysis of historical price volatility of the Company's common stock. The expected volatility is based on the daily percentage change in the price of the stock over a period equal to the expected term of the option grant.
	(3)    Represents the U.S. Treasury yield over the expected term of the option grant.
	-4	Represents the period of time that options granted are expected to be outstanding. Based on analysis of historical option exercise activity, the Company has determined that all employee groups exhibit similar exercise and post-vesting termination behavior.
	As of December 31, 2014, there was $27,959,369 of unrecognized compensation cost related to share-based payments which is expected to be recognized over the remaining vesting periods, with a weighted-average period of 2.1 years.
	A summary of the status of the Company’s employee stock option plan at December 31, 2014, 2013 and 2012, and changes during the same periods are presented in the tables and narrative below and have been adjusted to reflect the 2 for 1 common stock split effected in the form of a 100% stock dividend on December 31, 2014.
		2014
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	18,000			$	12
	Granted	5,757			15
	Exercised	(5,224	)		11						$	26,618
	Forfeited	(704	)		13
	Outstanding at End of Year	17,829			13				3.5 Yrs		$	90,759
	Exercisable at End of Year	4,564			$	12			2.3 Yrs		$	28,342
		2013
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	17,722			$	11
	Granted	5,462			13
	Exercised	(4,450	)		8						$	20,884
	Forfeited	(734	)		12
	Outstanding at End of Year	18,000			12				3.4 Yrs		$	85,633
	Exercisable at End of Year	5,490			$	12			2.3 Yrs		$	28,302
		2012
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	15,110			$	11
	Granted	5,282			10
	Exercised	(1,378	)		8						$	3,810
	Forfeited	(1,292	)		11
	Outstanding at End of Year	17,722			11				3.4 Yrs		$	11,730
	Exercisable at End of Year	6,006			$	10			2.2 Yrs		$	7,617
	A summary of the status of the Company’s non-vested employee stock option activity for the years ended December 31, 2014, 2013, and 2012, are presented in the table and narrative below:
		2014							2013					2012
		Shares			Wtd. Avg				Shares			Wtd. Avg		Shares		Wtd. Avg
		0			Grant				0			Grant		0		Grant
					Date							Date				Date
					Fair Value							Fair Value				Fair Value
	Nonvested Stock Options at Beginning of Year	12,508			$	4			11,716			$	3	11,060		$	3
	Granted	5,757			4				5,462			4		5,282		3
	Vested	(4,346	)		3				(4,044	)		3		(3,872	)	3
	Forfeited	(654	)		4				(626	)		4		(754	)	3
	Nonvested Stock Options at End of Year	13,265			$	4			12,508			$	4	11,716		$	3
	Non-employee Director Stock Option Plan
	In 2012, an Amended and Restated Non-employee Director Stock Option Plan, covering a total of 1,000,000 shares of common stock, was approved by shareholders replacing a prior plan. The Company has granted options on 266,000 shares (net of shares from canceled options) under the new director plan and 1,086,480 shares (net of shares from exercised/canceled options) under a prior plan through December 31, 2014. Under the shareholder approved plans, the option exercise price equals the stock's market price on date of grant. The options vest after six months, and expire after ten years.
The fair value of each option grant in the Non-employee Director Stock Option Plans was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the indicated periods:
	2014				2013				2012
Dividend yield (1)	2.2		%		2.7		%		2.6		%
Expected volatility (2)	39.6		%		45.9		%		44.5		%
Risk-free interest rate (3)	2.5		%		1.9		%		1.7		%
Expected term of options (in years) (4)	6.4				7				6.8
Weighted-average grant-date fair value	$	5			$	5			$	4
(1)    Represents the Company's estimated cash dividend yield over the expected term of option grant.
-2	Amount is determined based on analysis of historical price volatility of the Company's common stock. The expected volatility is based on the daily percentage change in the price of the stock over a period equal to the expected term of the option grant.
(3)    Represents the U.S. Treasury yield over the expected term of the option grant.
-4	Represents the period of time that options granted are expected to be outstanding. Based on analysis of historical option exercise activity, the Company has determined that non-employee directors exhibit similar exercise and post-vesting termination behavior.
As of December 31, 2014, there were no unrecognized compensation costs related to share-based payments under this plan.
A summary of the status of the Company’s Non-employee Director Stock Option Plan at December 31, 2014, 2013, and 2012, and changes during the same periods are presented in the tables and narrative below:
	2014
	Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
	0			Ex. Price				Remaining		Intrinsic
								Contract Life		Value
										0
Outstanding at Beginning of Year	462			$	11
Granted	98			14
Exercised	(167	)		10						$	893
Forfeited	(12	)		16
Outstanding at End of Year	381			12				6.7 Yrs		$	2,137
Exercisable at End of Year	381			$	12			6.7 Yrs		$	2,137
	2013
	Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
	0			Ex. Price				Remaining		Intrinsic
								Contract Life		Value
										0
Outstanding at Beginning of Year	468			$	11
Granted	84			12
Exercised	(90	)		10						$	300
Forfeited	—			—
Outstanding at End of Year	462			11				6.4 Yrs		$	2,491
Exercisable at End of Year	462			$	11			6.4 Yrs		$	2,491
	2012
	Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
	0			Ex. Price				Remaining		Intrinsic
								Contract Life		Value
										0
Outstanding at Beginning of Year	384			$	11
Granted	84			11
Exercised	—			—
Forfeited	—			—
Outstanding at End of Year	468			11				6.4 Yrs		$	225
Exercisable at End of Year	468			$	11			6.4 Yrs		$	225
A summary of the status of the Company’s nonvested Nonemployee Director Stock Option Plan activity for the years ended December 31, 2014, 2013, and 2012, are presented in the table and narrative below:
	2014							2013					2012
	Shares			Wtd. Avg				Shares			Wtd. Avg		Shares		Wtd. Avg
	0			Grant Date				0			Grant Date		0		Grant Date
				Fair Value							Fair Value				Fair Value
Nonvested Stock Options at Beginning of Year	—			$	—			—			$	—	—		$	—
Granted	98			5				84			5		84		4
Vested	(98	)		5				(84	)		5		(84	)	4
Forfeited	—			—				—			—		—		—
Nonvested stock options at End of Year	—			$	—			—			$	—	—		$	—
Employee Stock Purchase Plan
In 2013, the Gentex Corporation Employee Stock Purchase Plan covering 2,000,000 shares of common stock was approved by the shareholders, replacing a prior plan. Under such plan, the Company sells shares at 85% of the stock’s market price at date of purchase. Under ASC 718, the 15% discounted value is recognized as compensation expense. The following table summarizes shares sold to employees under the 2014 Plan and the prior plan in the years ended December 31, 2014, 2013 and 2012.
Plan	2014			2013			2012		Cumulative Shares Issued in 2014		Weighted Average Fair Value 2013
2013 Employee Stock Purchase Plan	137,028			102,924			—		239,952		$	12.99
2003 Employee Stock Purchase Plan	—			52,340			204,996		2,400,000		$	8.51
Total shares sold to employees	137,028			155,264			204,996
Restricted Stock Plan
In 2008, an amendment to the Company’s Second Restricted Stock Plan was approved by shareholders. The Plan amendment increased the maximum number of shares that may be subject to awards to 4,000,000 shares and to extend the Plan’s termination date to February 21, 2018. The purpose of this plan is to permit grants of shares, subject to restrictions, to key employees of the Company as a means of retaining and rewarding them for long-term performance and to increase their ownership in the Company. Shares awarded under the plan entitle the shareholder to all rights of common stock ownership except that the shares may not be sold, transferred, pledged, exchanged or otherwise disposed of during the restriction period. The restriction period is determined by a committee, appointed by the Board of Directors, but may not exceed ten years. The Company has 1,577,580 shares outstanding under the plan as of December 31, 2014. During 2014, 2013, and 2012, 431,880, 374,180 and 451,460 shares, respectively, were granted with a restriction period of five years at market prices ranging from $13.39 to $18.31 in 2014, $10.12 to $16.42 in 2013, and $8.64 to $12.23 in 2012, and has unearned stock-based compensation of $12,327,280 associated with these restricted stock grants. The unearned stock-based compensation related to these grants is being amortized to compensation expense over the applicable restriction periods. Amortization expense of restricted stock for years ended December 31, 2014, 2013 and 2012 was $3,095,136, $2,760,446. and $2,108,583 respectively.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Contingencies	CONTINGENCIES
	On June 25, 2012, American Vehicular Sciences LLC (“AVS”) filed four patent infringement complaints in the United States District Court in the Eastern District of Texas, which named the Company and one of two of its customers as co-defendants. In two of the complaints (#6:12-cv-00413 and #6:12-cv-00406), AVS alleged that the Company's SmartBeam® product infringed one patent owned by AVS. In the other two complaints (#6:12-cv-00410 and #6:12-cv-00415), AVS alleged that the Company's monitoring system products infringe two other patents owned by AVS. The Company was served with the four complaints on July 27, 2012. On October 5, 2012, the Company submitted its answers to all four complaints.
	On December 28, 2012, in the ordinary course of business, the Company entered into a settlement/license agreement (“agreement”) with AVS, settling all pending litigation. The cost associated with the agreement was accrued by the Company and reflected in its financial results as of December 31, 2012. As a result of the agreement, the United States District Court in the Eastern District of Texas has ordered that the Company is dismissed with prejudice as a defendant in the complaints filed by AVS.
	The Company is periodically involved in legal proceedings, legal actions and claims arising in the normal course of business, including proceedings relating to product liability, intellectual property, safety and health, employment and other matters. Such matters are subject to many uncertainties and outcomes are not predictable. The Company does not believe, however, that at the current time any of these matters constitute material pending legal proceedings that will have a material adverse effect on the financial position or future results of operations of the Company.

Segment_Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING
	ASC 280, “Disclosures About Segments of an Enterprise and Related Information,” requires that a public enterprise report financial and descriptive information about its reportable operating segments subject to certain aggregation criteria and quantitative thresholds. Operating segments are defined by ASC 280 as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision-makers in deciding how to allocate resources and in assessing performance.
		2014				2013			2012
	Revenue:
	Automotive Products
	United States	$	444,921,897			$	400,654,021		$	382,308,501
	Germany	262,505,346				244,949,664			239,081,723
	Japan	133,758,799				123,884,470			100,422,507
	Other	498,936,232				374,499,972			355,160,210
	Other	35,378,885				27,876,044			22,586,580
	Total	$	1,375,501,159			$	1,171,864,171		$	1,099,559,521
	Income (Loss) from Operations:
	Automotive Products	$	386,762,986			$	298,465,299		$	231,713,972
	Other	12,071,188				6,276,514			2,741,260
	Total	$	398,834,174			$	304,741,813		$	234,455,232
	Assets:
	Automotive Products	$	1,333,615,389			$	1,290,801,674		$	619,337,527
	Other	8,841,958				9,001,278			8,010,779
	Corporate	680,082,682				464,285,482			638,343,029
	Total	$	2,022,540,029			$	1,764,088,434		$	1,265,691,335
	Depreciation & Amortization:
	Automotive Products	$	75,320,999			$	58,723,222		$	47,976,800
	Other	321,426				316,836			317,534
	Corporate	1,733,880				3,814,097			1,885,489
	Total	$	77,376,305			$	62,854,155		$	50,179,823
	Capital Expenditures:
	Automotive Products	$	71,032,115			$	54,020,792		$	113,611,526
	Other	145,704				301,697			228,635
	Corporate	1,341,168				1,057,968			3,634,288
	Total	$	72,518,987			$	55,380,457		$	117,474,449
	Other includes Fire Protection Products and Dimmable Aircraft Windows. Dimmable Aircraft Window net sales continued to increase during 2012, 2013 and 2014, which resulted in income from operations for each of the three years presented in the “Other” category.
	Corporate assets are principally cash and cash equivalents, investments, deferred income taxes and corporate fixed assets. Substantially all long-lived assets are located in the U.S.
	Automotive Products revenues in the “Other” category are sales to customer automotive manufacturing plants in Korea, Mexico, Canada, Hungary, China, and the United Kingdom as well as other foreign automotive customers. Most of the Company’s non-U.S. sales are invoiced and paid in U.S. dollars. During the years ended December 31, 2014, 2013 and 2012, approximately 6% , 7% and 8% of the Company’s net sales were invoiced and paid in foreign currencies respectively.
	In 2014, the Company had four automotive customers (includes direct sales to OEM customers and sales through their Tier 1 suppliers), which individually accounted for 10% or more of net sales as follows:
		Toyota Motor Corporation		VW/Audi			Hyundai/Kia		Daimler AG		General Motors		FCA Group
	2014	12	%	14	%		#		10	%	#		11	%
	2013	13	%	14	%		#		11	%	#		#
	2012	14	%	14	%		11	%	11	%	10	%	#
	# - Less than 10 percent.

Quarterly_Financial_Informatio

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (Unaudited)	QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
	The following table sets forth selected financial information for all of the quarters during the years ended December 31, 2014 and 2013 (in thousands, except per share data):
		First				Second				Third				Fourth
		2014		2013		2014		2013		2014		2013		2014		2013
	Net Sales	$	335,739	$	269,499	$	338,437	$	286,974	$	350,914	$	288,622	$	350,411	$	326,770
	Gross Profit	131,299		93,464		134,292		102,613		138,626		105,962		134,673		128,694
	Operating Income	97,178		63,854		99,835		71,596		103,206		73,656		98,615		95,636
	Net Income	68,566		45,431		76,727		52,097		72,337		55,521		70,975		69,881
	Earnings Per Share (Diluted)	$	0.24	$	0.16	$	0.26	$	0.18	$	0.25	$	0.19	$	0.24	$	0.24
	Earnings Per Share (Basic)	$	0.24	$	0.16	$	0.27	$	0.18	$	0.25	$	0.2	$	0.24	$	0.24

Comprehensive_Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2014
Comprehensive Income [Abstract]
Comprehensive Income	Comprehensive Income
	Comprehensive income reflects the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. For the Company, comprehensive income represents net income adjusted for unrealized gains and losses on certain investments, foreign currency translation adjustments, and unrealized movement in derivative financial instruments designated as hedges.
		For the Twelve Months ended December 31,
		2014				2013				2012
	Foreign currency translation adjustments:
	Balance at beginning of period	$	2,507,922			$	2,458,933			$	2,129,957
	Other comprehensive income before reclassifications	(1,104,023		)		48,989				328,976
	Amounts reclassified from accumulated other comprehensive income	—				—				—
	Net current-period change	(1,104,023		)		48,989				328,976
	Balance at end of period	1,403,899				2,507,922				2,458,933
	Unrealized gains(losses) on available-for-sale securities:
	Balance at beginning of period	19,467,441				15,111,778				10,412,246
	Other comprehensive income before reclassifications	1,536,416				16,139,845				10,138,902
	Amounts reclassified from accumulated other comprehensive income	(10,135,535		)		(11,784,182		)		(5,439,370		)
	Net current-period change	(8,599,119		)		4,355,663				4,699,532
	Balance at end of period	10,868,322				19,467,441				15,111,778
	Unrealized gains (losses) on derivatives:
	Balance at beginning of period	—				—				—
	Other comprehensive income before reclassifications	(959,206		)		—				—
	Amounts reclassified from accumulated other comprehensive income	—				—				—
	Net current-period change	(959,206		)		—				—
	Balance at end of period	(959,206		)		—				—
	Accumulated other comprehensive income, end of period	$	11,313,015			$	21,975,363			$	17,570,711
	All amounts are shown net of tax. Amounts in parentheses indicate debits.
	The following table presents details of reclassifications out of other comprehensive income for the twelve months ended December 31, 2014, 2013 and 2012.
	Details about Accumulated Other Comprehensive Income Components		Amounts Reclassified from Other Comprehensive Income											Affected Line item in the Statement of Consolidated Income
			For the Twelve Months ended December 31,
			2014				2013				2012
	Unrealized gains and (losses) on available-for-sale securities
	Realized gain (loss) on sale of securities		$	15,593,131			$	18,129,511			$	8,368,261		Other, net
	Provision for Income Taxes		(5,457,596		)		(6,345,329		)		(2,928,891		)	Provision for Income Taxes
	Total reclassifications for the period		$	10,135,535			$	11,784,182			$	5,439,370		Net of tax

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS
	On September 27, 2013, the Company completed the acquisition of certain assets and liabilities of Johnson Controls, Inc. related to HomeLink®. Prior to the acquisition, the Company was a licensee of HomeLink® which allowed for incorporation of HomeLink® into the Company’s rearview mirror products, that are installed in automobiles. The aggregate purchase price for the Business paid at the closing was approximately $700 million subject to working capital adjustments. During the first quarter of 2014 the Company finalized purchase accounting.
	The Company funded the transaction using a combination of cash on hand of approximately $423 million and debt financing. The Company’s debt financing included net proceeds from the Company’s Credit Agreement as described in Note 2.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND INTANGIBLE ASSETS
	On September 27, 2013, the Company recorded Goodwill of $337.6 million related to the HomeLink acquisition detailed further in Note 10. As of December 31, 2013, the Company adjusted recorded Goodwill to $307.4 million resulting from finalization of purchase accounting estimates, during the first quarter of 2014. The carrying value of Goodwill as of December 31, 2014 and December 31, 2013 was $307.4 million as set forth in the table below.
		Carrying Amount
	Balance as of December 31, 2013	$	307,365,845
	Acquisitions	—
	Divestitures	—
	Impairments	—
	Other	—
	Balance as of December 31, 2014	$	307,365,845
	The Company's impairment testing in the fourth quarter of 2014 indicated that the estimated fair value of the Automotive reporting unit exceeded its corresponding carrying amount including goodwill by approximately 248%. And as such, the Company has not recognized any impairment of goodwill in the current period. The Company continuously monitors for events and circumstances that could negatively impact the key assumptions in determining fair value thus resulting in the need for interim testing, including long-term revenue growth projections, profitability, discount rates, recent market valuations from transactions by comparable companies, volatility in the Company's market capitalization, and general industry, market and macro-economic conditions, no such matters were noted in the current period.
	The Intangible assets and related change in carrying values are set forth in the table belows as of December 31, 2014 and December 31, 2013.
	Other Intangible Assets	Gross		Accumulated Amortization			Net		Assumed Useful Life
	HomeLink®Trade Names and Trademarks	$	52,000,000	$	—		$	52,000,000	Indefinite
	HomeLink® Technology	180,000,000		(18,750,000		)	$	161,250,000	12 years
	Existing Customer Platforms	43,000,000		(5,375,000		)	$	37,625,000	10 years
	Exclusive Licensing Agreement	96,000,000		—			$	96,000,000	Indefinite
	Total other identifiable intangible assets	371,000,000		(24,125,000		)	346,875,000
	As of December 31, 2013:
	Other Intangible Assets	Gross		Accumulated Amortization			Net		Assumed Useful Life
	HomeLink®Trade Names and Trademarks	$	52,000,000	$	—		$	52,000,000	Indefinite
	HomeLink® Technology	180,000,000		(3,750,000		)	$	176,250,000	12 years
	Existing Customer Platforms	43,000,000		(1,075,000		)	$	41,925,000	10 years
	Exclusive Licensing Agreement	96,000,000		—			$	96,000,000	Indefinite
	Total other identifiable intangible assets	$	371,000,000	$	(4,825,000	)	$	366,175,000
	Accumulated amortization on patents and intangible assets was approximately $35.2 million and $13.4 million at December 31, 2014 and 2013, respectively. Amortization expense on patents and other intangible assets was approximately $22.0 million, $7.9 million, and $1.7 million in 2014, 2013 and 2012, respectively. At December 31, 2014, patents had a weighted average amortized life of 10 years.
	Excluding the impact of any future acquisitions, the Company anticipates amortization expense including patents and other intangible assets for each of the years ended December 31, 2015, 2016, 2017, 2018 and 2019 to be approximately $22 million annually.

Stock_Split

Stock Split	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stock Split	STOCK SPLIT
	On December 5, 2014, the Company announced that its Board of Directors approved a two-for-one split of our outstanding shares of common stock to be effected in the form of a 100% stock dividend. On December 31, 2014, shareholders of record at the close of business on December 17, 2014, were issued one additional share of common stock for each share owned by such shareholder. The stock split increased the number of shares of common stock outstanding from approximately 147.6 million to approximately 295.2 million. Share and per-share amounts (including stock options and restricted stock) shown in the consolidated financial statements and related notes reflect the split. The total number of authorized common shares and the par value thereof was not changed by the split.

Summary_of_Significant_Account1

Summary of Significant Accounting and Reporting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Consolidation	Consolidation
	The consolidated financial statements include the accounts of Gentex Corporation and all of its wholly-owned subsidiaries (together the “Company”). All significant intercompany accounts and transactions have been eliminated.
Cash Equivalents	Cash Equivalents
	Cash equivalents consist of funds invested in bank accounts and money market funds that have daily liquidity.
Allowance For Doubtful Accounts	Allowance For Doubtful Accounts
	The Company bases its allowances for doubtful accounts related to receivables on historical credit and collections experience, and the specific identification of other potential problems, including the economic climate. Actual collections can differ, requiring adjustments to the allowances. Individual accounts receivable balances are evaluated on a monthly basis, and those balances considered uncollectible are charged to the allowance. Collections of amounts previously written off are recorded as an increase to the allowance.
Investments	Investments
	The Company follows the provisions of ASC 820, “Fair Value Measurements and Disclosures” for its financial assets and liabilities, and for its non-financial assets and liabilities subject to fair value measurements. ASC 820 provides a framework for measuring the fair value of assets and liabilities. This framework is intended to provide increased consistency in how fair value determinations are made under various existing accounting standards that permit, or in some cases, require estimates of fair-market value. This standard also expanded financial statement disclosure requirements about a company’s use of fair-value measurements, including the effect of such measure on earnings. The cost of securities sold is based on the specific identification method.
	The Company’s investment securities (common stocks and mutual funds) are classified as available for sale and are stated at fair value based on quoted market prices, and as such are classified as Level 1 assets.
	ASC 320, “Accounting for Certain Investments in Debt and Equity Securities,” as amended and interpreted, provides guidance on determining when an investment is other-than-temporarily impaired. The Company reviews its fixed income and equity investment portfolio for any unrealized losses that would be deemed other-than-temporary and require the recognition of an impairment loss in income. If the cost of an investment exceeds its fair value, the Company evaluates, among other factors, general market conditions, the duration and extent to which the fair value is less than cost, and the Company’s intent and ability to hold the investments. Management also considers the type of security, related-industry and sector performance, as well as published investments ratings and analyst reports, to evaluate its portfolio. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded and new cost basis in the investment is established. If market, industry, and/or investee conditions deteriorate, the Company may incur future impairments. No investments were considered to be other-than-temporary impaired in 2014 and 2013.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	The Company’s financial instruments consist of cash and cash equivalents, investments, accounts receivable accounts payable, short and long term debt. The Company’s estimate of the fair values of these financial instruments approximates their carrying amounts at December 31, 2014 and 2013.
Inventories	Inventories
	Inventories include material, direct labor and manufacturing overhead and are valued at the lower of first-in, first-out (FIFO) cost or market.
Plant and Equipment	Plant and Equipment
	Plant and equipment are stated at cost. Depreciation and amortization are computed for financial reporting purposes using the straight-line method, with estimated useful lives of 7 to 30 years for buildings and improvements, and 3 to 10 years for machinery and equipment.
Impairment or Disposal of Long-Lived Assets	Impairment or Disposal of Long-Lived Assets
	The Company reviews long-lived assets, including property, plant and equipment and other intangible assets with definite lives, for impairment whenever events or changes in circumstances indicate that the asset’s carrying amount may not be recoverable. The Company conducts its long-lived asset impairment analysis in accordance with ASC 360-10-15, “Impairment or Disposal of Long-Lived Assets.” ASC 360-10-15 requires the Company to group assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities and evaluate the asset group against the sum of the undiscounted future cash flows. If the undiscounted cash flows do not indicate the carrying amount of the asset is recoverable, an impairment charge is measured as the amount by which the carrying amount of the asset group exceeds its fair value based on discounted cash flow analysis or appraisals.
Patents	Patents
	The Company’s policy is to capitalize costs incurred to obtain patents. The cost of patents is amortized over their useful lives. The cost of patents in process is not amortized until issuance. The Company periodically obtains intellectual property rights, in the ordinary course of business, and the cost of the rights are amortized over their useful lives.
Goodwill and Other Intangible Assets	Goodwill and Intangible Assets
	Goodwill reflects the cost of an acquisition in excess of the fair values assigned to identifiable net assets acquired. The Company reviews goodwill for impairment during the fourth quarter on an annual basis or more frequently if events or changes in circumstances indicate that goodwill might be impaired. The Company performs an impairment review for its automotive reporting unit, which has been determined to be one of the Company’s reportable segments using a fair value method which incorporates management’s judgments and assumptions and may incorporate third party valuations. The fair value of a reporting unit refers to the price that would be received to sell the unit as a whole in an orderly transaction between market participants at the measurement date. In estimating the fair value, the Company uses a combination of widely accepted valuation methodologies incorporating certain judgments and assumptions to arrive at the fair value of the reporting unit.
	The assumptions included in the impairment tests require judgment, and changes to these inputs could impact the results of the calculations which could result in an impairment charge in future periods if the carrying amount of the reporting unit exceeds its calculated fair value. Other than management's internal projections of future cash flows, the primary assumptions used in the impairment tests were the weighted-average cost of capital and long-term growth rates. Although the Company's cash flow forecasts are based on assumptions that are considered reasonable by management and consistent with the plans and estimates management is using to operate the underlying business, there are significant judgments in determining the expected future cash flows attributable to a reporting unit. There have been no impairment charges booked currently or in prior periods in which goodwill existed.
	Indefinite lived intangible assets are also subject to annual impairment testing or more frequently if indicators of impairment are identified. Management judgment and assumptions are required in determining the underlying fair value of the indefinite lived intangible assets. While the Company believes the judgments and assumptions used in determining fair value are reasonable and no impairment existed at December 31, 2014 or December 31, 2013, different assumptions could change the estimated fair values and, therefore, impairment charges could be required, which could be material to the consolidated financial statements. The indefinite lived intangible assets were not impaired as a result of the annual test prepared by management for either period presented.
Revenue Recognition	Revenue Recognition
	The Company’s revenue is generated from sales of its products. Sales are recognized when the product is shipped and legal title has passed to the customer. The Company does not generate sales from arrangements with multiple deliverables.
	In May 2014 the Financial Accounting Standards Board (FASB) issued the Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606), that will supersede nearly all existing revenue recognition guidance under US GAAP. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The standard will be effective for public entities for annual and interim periods beginning after December 15, 2016.
	Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach. Entities electing the full retrospective adoption will apply the standard to each period presented in the financial statements. This means that entities will have to apply the new guidance as if it had been in effect since the inception of all its contracts with customers presented in the financial statements. Entities that elect the modified retrospective approach will apply the guidance retrospectively only to the most current period presented in the financial statements. This means that entities will have to recognize the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings at the date of initial application. The new revenue standard will be applied to contracts that are in progress at the date of initial application.
	The Company is currently evaluating which adoption method it plans to use and is assessing the potential effect the new standard will have on its consolidated financial statements.
Advertising and Promotional Materials	Advertising and Promotional Materials
	All advertising and promotional costs are expensed as incurred
Repairs and Maintenance	Repairs and Maintenance
	Major renewals and improvements of property and equipment are capitalized, and repairs and maintenance are expensed as incurred.
Self-Insurance	Self-Insurance
	The Company is self-insured for a portion of its risk on workers’ compensation and employee medical costs. The arrangements provide for stop loss insurance to manage the Company’s risk. Operations are charged with the cost of claims reported and an estimate of claims incurred but not reported based upon historical claims lag information and other data.
Product Warranty	Product Warranty
	The Company periodically incurs product warranty costs. Any liabilities associated with product warranty are estimated based on known facts and circumstances and are not significant at December 31, 2014, 2013 and 2012. The Company does not offer extended warranties on its products.
Income Taxes	Income Taxes
	The provision for income taxes is based on the earnings reported in the consolidated financial statements. Deferred income tax assets and liabilities are computed for differences between the financial statement and tax basis of assets and liabilities that will result in taxable or deductible amounts in the future. Such deferred income tax asset and liability computations are based on enacted tax laws and rates.
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss)
	Comprehensive income reflects the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. For the Company, comprehensive income represents net income adjusted for unrealized gains and losses on certain investments, unrealized gains and losses on certain derivative financial instruments and foreign currency translation adjustments and is further detailed in Note 9 to the Consolidated Financial Statements.
Foreign Currency Translation	Foreign Currency Translation
	The financial position and results of operations of the Company’s foreign subsidiaries are measured using the local currency as the functional currency. Assets and liabilities are translated at the exchange rate in effect at year-end. Income statement accounts are translated at the average rate of exchange in effect during the year. The resulting translation adjustment is recorded as a separate component of shareholders’ investment. Gains and losses arising from re-measuring foreign currency transactions into the appropriate currency are included in the determination of net income.
Derivative Financial Instruments	Derivative Financial Instruments
	The Company accounts for derivative financial instruments in accordance with the guidance provided in ASC Topic 815, Derivatives and Hedging. The guidance requires that all derivative instruments be recognized as assets or liabilities on the consolidated balance sheets and measured at fair value. For derivatives designated as cash flow hedges, fair value changes in the effective portion of the hedging instrument are recognized in accumulated other comprehensive income on the consolidated balance sheets until the forecasted transaction affects earnings of the consolidated entity. Any ineffective portion of the fair value change is recognized in earnings immediately. At December 31, 2014, there was no ineffectiveness.
	The Company seeks to reduce exposure to interest rate fluctuations through the use of an interest rate swap agreement. The Company does not buy and sell such financial instruments for investment or speculative purposes. The Company is exposed to credit loss in the event of nonperformance by the counterparties on derivative contracts. It is the Company’s practice to manage its credit risk on these transactions by dealing highly rated financial institutions.
Stock-Based Compensation Plans	Stock-Based Compensation Plans
	The Company accounts for stock-based compensation using the fair value recognition provisions of ASC 718, “Compensation - Stock Compensation.” As described more fully in Note 5, the Company provides compensation benefits under two stock option plans, a restricted stock plan and an employee stock purchase plan.
Estimates	Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
New Accounting Standards	New Accounting Standards
	In May 2014 the Financial Accounting Standards Board (FASB) issued the Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606), that will supersede nearly all existing revenue recognition guidance under US GAAP. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The standard will be effective for public entities for annual and interim periods beginning after December 15, 2016.
	Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach. Entities electing the full retrospective adoption will apply the standard to each period presented in the financial statements. This means that entities will have to apply the new guidance as if it had been in effect since the inception of all its contracts with customers presented in the financial statements. Entities that elect the modified retrospective approach will apply the guidance retrospectively only to the most current period presented in the financial statements. This means that entities will have to recognize the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings at the date of initial application. The new revenue standard will be applied to contracts that are in progress at the date of initial application.
	The Company is currently evaluating which adoption method it plans to use and is assessing the potential effect the new standard will have on its consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting and Reporting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Allowance For Doubtful Accounts	The following table presents the activity in the Company’s allowance for doubtful accounts:
		Beginning		Net			Deductions				Ending
		Balance		Additions/			and Other				Balance
				(Reductions)			Adjustments
				to Costs and
				Expenses
	Year Ended December 31, 2014:
	Allowance for Doubtful Accounts	$	3,202,388	$	(300,000	)	$	(191,140	)		$	2,711,248
	Year Ended December 31, 2013:
	Allowance for Doubtful Accounts	$	3,400,000	$	—		$	(197,612	)		$	3,202,388
	Year Ended December 31, 2012:
	Allowance for Doubtful Accounts	$	3,400,000	$	(577	)	577*				$	3,400,000
	*Represents excess recoveries and other adjustments over accounts written off.
Schedule of Assets or Liabilities Having Recurring Measurements	Assets or liabilities that have recurring fair value measurements are shown below as of December 31, 2014 and December 31, 2013:
				Fair Value Measurements at Reporting Date Using
		Total as of		Quoted Prices in			Significant Other				Significant
				Active Markets			Observable				Unobservable
				for Identical			Inputs				Inputs
				Assets
	Description	31-Dec-14		(Level I)			(Level 2)				(Level 3)
	Cash & Cash Equivalents	$	497,429,804	$	497,429,804		$	—			$	—
	Short-Term Investments:
	Other	1,021		1,021
	Long-Term Investments:
	Corporate Bonds	—
	Common Stocks	24,648,451		24,648,451			—				—
	Mutual Funds – Equity	89,994,116		89,994,116			—				—
	Total	$	612,073,392	$	612,073,392		$	—			$	—
				Fair Value Measurements at Reporting Date Using
		Total as of		Quoted Prices in			Significant Other				Significant
				Active Markets			Observable				Unobservable
				for Identical			Inputs				Inputs
				Assets
	Description	December 31, 2013		(Level I)			(Level 2)				(Level 3)
	Cash & Cash Equivalents	$	309,591,724	$	309,591,724		$	—			$	—
	Long-Term Investments:
	Common Stocks	33,282,439		33,282,439			—				—
	Mutual Funds – Equity	73,723,083		73,723,083			—				—
	Total	$	416,597,246	$	416,597,246		$	—			$	—
Schedule of Amortized Cost, Unrealized Gains And Losses, And Market Value of Investment Securities	The amortized cost, unrealized gains and losses, and market value of investment securities are shown as of December 31, 2014 and 2013:
		Unrealized
	2014	Cost		Gains			Losses				Market Value
	Short-Term Investments:
	Other	1,021									1,021
	Long-Term Investments:
	Common Stocks	17,069,742		7,933,717			(355,008		)		24,648,451
	Mutual Funds-Equity	80,852,329		9,922,204			(780,417		)		89,994,116
	Total	$	97,923,092	$	17,855,921		$	(1,135,425	)		$	114,643,588
		Unrealized
	2013	Cost		Gains			Losses			Market Value
	Long-Term Investments:									—
	Common Stocks	22,799,035		10,532,007			(48,603	)		33,282,439
	Mutual Funds-Equity	54,256,577		19,466,506			—			73,723,083
	Total	$	77,055,612	$	29,998,513		(48,603	)		$	107,005,522
Schedule of Unrealized Losses on Investments	Unrealized losses on investments as of December 31, 2014 are as follows:
		Aggregate Unrealized Losses		Aggregate Fair Value
	Less than one year	$	1,135,425	$	19,972,258
	Unrealized losses on investments as of December 31, 2013 are as follows:
		Aggregate Unrealized Losses		Aggregate Fair Value
	Less than one year	$	48,603	$	1,886,080
Schedule of Inventories	Inventories consisted of the following as of December 31, 2014 and 2013:
		2014		2013
	Raw materials	$	90,780,320	$	75,081,810
	Work-in-process	24,135,944		21,409,976
	Finished goods	26,841,620		23,582,378
	Total Inventory	$	141,757,884	$	120,074,164
Schedule of Earnings Per Share Basic and Diluted	The following table reconciles the numerators and denominators used in the calculations of basic and diluted earnings per share (EPS) for each of the last three years adjusted for the 2 for 1 common stock split effected in the form of a 100% stock dividend issued on December 31, 2014:
		2014		2013			2012
	Numerators:
	Numerator for both basic and diluted EPS, net income	$	288,604,579	$	222,929,949		$	168,586,840
	Denominators:
	Denominator for basic EPS, weighted-average common shares outstanding	290,952,123		286,920,036			286,195,060
	Potentially dilutive shares resulting from stock option plans	3,347,236		1,628,306			1,741,002
	Denominator for diluted EPS	294,299,359		288,548,342			287,936,062

Debt_and_Financing_Arrangement1

Debt and Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of notional amount of derivative financial instruments	The notional amount of the Company's derivative instruments are as follows:
		31-Dec-14		31-Dec-13		31-Dec-12
	Interest Rate swap	$	150,000,000	$	—	$	—
Schedule of financial assets and liabilities measured at fair value in the consolidated balance sheets	The following table sets forth financial assets and liabilities measured at fair value in the consolidated balance sheets and the respective pricing levels to which the fair value measurements are classified within the fair value hierarchy. The Company uses the market approach to derive the value of its level 2 fair value measurements. Interest rate swaps are valued using publicized swap curves.
	Fair Value Measurements
	Quoted Prices with Other Observable Inputs (Level 2)
		31-Dec-14		31-Dec-13		31-Dec-12
	Financial assets:
	Interest Rate Swap Asset	$	—	$	—	$	—
	Financial Liabilities:
	Interest Rate Swap Liability (Other Accrued Liabilities)	$	1,475,702	$	—	$	—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	The Company follows the provisions of the Financial Accounting Standards Codification 740 (“ASC 740”), “Income Taxes.” A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
		2014				2013				2012
	Beginning of year	$	7,351,000			$	4,168,000			$	2,476,000
	Additions based on tax positions related to the current year	1,328,000				1,595,000				785,000
	Additions for tax positions in prior years	634,000				1,633,000				907,000
	Reductions for tax positions in prior years	(676,000		)		(45,000		)		—
	Reductions as a result of a lapse of the applicable statute of limitations	(349,000		)		—				—
	End of year	$	8,288,000			$	7,351,000			$	4,168,000
Schedule of Components of Provision For Income Taxes	The components of the provision for income taxes are as follows:
		2014				2013				2012
	Currently payable:
	Federal	$	108,689,911			$	95,285,094			$	76,507,760
	State	2,236,000				3,259,000				2,450,000
	Foreign	978,000				1,353,000				1,238,000
	Total	111,903,911				99,897,094				80,195,760
	Net deferred:
	Primarily federal	14,818,000				5,237,000				843,000
	Provision for income taxes	$	126,721,911			$	105,134,094			$	81,038,760
Schedule of Effective Income Tax Rates Different From Statutory Federal Income Tax Rates	The effective income tax rates are different from the statutory federal income tax rates for the following reasons:
		2014			2013			2012
	Statutory federal income tax rate	35	%		35	%		35	%
	State income taxes, net of federal income tax benefit	0.3			0.6			0.6
	Domestic production exclusion	(2.60	)		(3.1	)		(2.9	)
	Research tax credit (1)	(2.00	)		(0.4	)		—
	Other	(0.20	)		(0.1	)		(0.2	)
	Effective income tax rate	30.5	%		32	%		32.5	%
	1) - Research tax credits applied in 2014 related to prior tax year amended tax filings
Schedule of Deferred Income Tax Assets And Liabilities	The tax effect of temporary differences which give rise to deferred income tax assets and liabilities at December 31, 2014 and 2013, are as follows:
		2014								2013
		Current				Non-Current				Current			Non-Current
	Assets:
	Accruals not currently deductible	$	2,605,711			$	224,803			$	2,970,671		$	182,803
	Stock based compensation	13,508,845				2,508,304				13,290,429			2,202,940
	Impairment loss on available-for-sale securities	—				135,724				—			175,091
	Intangible Assets	—				—				—			169,913
	Other	4,440,407				19,765				4,713,241			40,203
	Total deferred income tax assets	20,554,963				2,888,596				20,974,341			2,770,950
	Liabilities:
	Excess tax over book depreciation	—				(46,017,949		)		—			(41,374,851		)
	Goodwill	—				(8,868,168		)		—			(1,792,968		)
	Unrealized gain on investments	—				(6,368,670		)		—			(10,482,468		)
	Intangible assets	—				(1,205,230		)		—			—
	Other	(1,117,956		)						(558,249		)
	Net deferred income taxes	$	19,437,007			$	(59,571,421	)		$	20,416,092		$	(50,879,337	)

StockBased_Compensation_Plans_

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Employee Stock Purchase Plan	The following table summarizes shares sold to employees under the 2014 Plan and the prior plan in the years ended December 31, 2014, 2013 and 2012.
	Plan	2014			2013			2012		Cumulative Shares Issued in 2014		Weighted Average Fair Value 2013
	2013 Employee Stock Purchase Plan	137,028			102,924			—		239,952		$	12.99
	2003 Employee Stock Purchase Plan	—			52,340			204,996		2,400,000		$	8.51
	Total shares sold to employees	137,028			155,264			204,996
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Weighted-Average Assumptions	The fair value of each option grant in the Employee Stock Option Plan was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the indicated periods:
		2014				2013				2012
	Dividend yield (1)	2.3		%		2.6		%		2.7		%
	Expected volatility (2)	38.5		%		44.7		%		45.5		%
	Risk-free interest rate (3)	1.7		%		1.3		%		0.8		%
	Expected term of options (in years) (4)	4.2				4				4.1
	Weighted-average grant-date fair value	$	4			$	4			$	3
	(1)    Represents the Company's estimated cash dividend yield over the expected term of option grant.
	-2	Amount is determined based on analysis of historical price volatility of the Company's common stock. The expected volatility is based on the daily percentage change in the price of the stock over a period equal to the expected term of the option grant.
	(3)    Represents the U.S. Treasury yield over the expected term of the option grant.
	-4	Represents the period of time that options granted are expected to be outstanding. Based on analysis of historical option exercise activity, the Company has determined that all employee groups exhibit similar exercise and post-vesting termination behavior.
Summary of Stock Option Activity	A summary of the status of the Company’s employee stock option plan at December 31, 2014, 2013 and 2012, and changes during the same periods are presented in the tables and narrative below and have been adjusted to reflect the 2 for 1 common stock split effected in the form of a 100% stock dividend on December 31, 2014.
		2014
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	18,000			$	12
	Granted	5,757			15
	Exercised	(5,224	)		11						$	26,618
	Forfeited	(704	)		13
	Outstanding at End of Year	17,829			13				3.5 Yrs		$	90,759
	Exercisable at End of Year	4,564			$	12			2.3 Yrs		$	28,342
		2013
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	17,722			$	11
	Granted	5,462			13
	Exercised	(4,450	)		8						$	20,884
	Forfeited	(734	)		12
	Outstanding at End of Year	18,000			12				3.4 Yrs		$	85,633
	Exercisable at End of Year	5,490			$	12			2.3 Yrs		$	28,302
		2012
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	15,110			$	11
	Granted	5,282			10
	Exercised	(1,378	)		8						$	3,810
	Forfeited	(1,292	)		11
	Outstanding at End of Year	17,722			11				3.4 Yrs		$	11,730
	Exercisable at End of Year	6,006			$	10			2.2 Yrs		$	7,617
Schedule of Non-Vested Stock Option Activity	A summary of the status of the Company’s non-vested employee stock option activity for the years ended December 31, 2014, 2013, and 2012, are presented in the table and narrative below:
		2014							2013					2012
		Shares			Wtd. Avg				Shares			Wtd. Avg		Shares		Wtd. Avg
		0			Grant				0			Grant		0		Grant
					Date							Date				Date
					Fair Value							Fair Value				Fair Value
	Nonvested Stock Options at Beginning of Year	12,508			$	4			11,716			$	3	11,060		$	3
	Granted	5,757			4				5,462			4		5,282		3
	Vested	(4,346	)		3				(4,044	)		3		(3,872	)	3
	Forfeited	(654	)		4				(626	)		4		(754	)	3
	Nonvested Stock Options at End of Year	13,265			$	4			12,508			$	4	11,716		$	3
Non-Employee Director Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Weighted-Average Assumptions	The fair value of each option grant in the Non-employee Director Stock Option Plans was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the indicated periods:
		2014				2013				2012
	Dividend yield (1)	2.2		%		2.7		%		2.6		%
	Expected volatility (2)	39.6		%		45.9		%		44.5		%
	Risk-free interest rate (3)	2.5		%		1.9		%		1.7		%
	Expected term of options (in years) (4)	6.4				7				6.8
	Weighted-average grant-date fair value	$	5			$	5			$	4
	(1)    Represents the Company's estimated cash dividend yield over the expected term of option grant.
	-2	Amount is determined based on analysis of historical price volatility of the Company's common stock. The expected volatility is based on the daily percentage change in the price of the stock over a period equal to the expected term of the option grant.
	(3)    Represents the U.S. Treasury yield over the expected term of the option grant.
	-4	Represents the period of time that options granted are expected to be outstanding. Based on analysis of historical option exercise activity, the Company has determined that non-employee directors exhibit similar exercise and post-vesting termination behavior.
Summary of Stock Option Activity	A summary of the status of the Company’s Non-employee Director Stock Option Plan at December 31, 2014, 2013, and 2012, and changes during the same periods are presented in the tables and narrative below:
		2014
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	462			$	11
	Granted	98			14
	Exercised	(167	)		10						$	893
	Forfeited	(12	)		16
	Outstanding at End of Year	381			12				6.7 Yrs		$	2,137
	Exercisable at End of Year	381			$	12			6.7 Yrs		$	2,137
		2013
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	468			$	11
	Granted	84			12
	Exercised	(90	)		10						$	300
	Forfeited	—			—
	Outstanding at End of Year	462			11				6.4 Yrs		$	2,491
	Exercisable at End of Year	462			$	11			6.4 Yrs		$	2,491
		2012
		Shares			Wtd. Avg.				Wtd. Avg.		Aggregate
		0			Ex. Price				Remaining		Intrinsic
									Contract Life		Value
											0
	Outstanding at Beginning of Year	384			$	11
	Granted	84			11
	Exercised	—			—
	Forfeited	—			—
	Outstanding at End of Year	468			11				6.4 Yrs		$	225
	Exercisable at End of Year	468			$	11			6.4 Yrs		$	225
Schedule of Non-Vested Stock Option Activity	A summary of the status of the Company’s nonvested Nonemployee Director Stock Option Plan activity for the years ended December 31, 2014, 2013, and 2012, are presented in the table and narrative below:
		2014							2013					2012
		Shares			Wtd. Avg				Shares			Wtd. Avg		Shares		Wtd. Avg
		0			Grant Date				0			Grant Date		0		Grant Date
					Fair Value							Fair Value				Fair Value
	Nonvested Stock Options at Beginning of Year	—			$	—			—			$	—	—		$	—
	Granted	98			5				84			5		84		4
	Vested	(98	)		5				(84	)		5		(84	)	4
	Forfeited	—			—				—			—		—		—
	Nonvested stock options at End of Year	—			$	—			—			$	—	—		$	—

Segment_Reporting_Tables

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Schedule of Automotive and Other Segment Reporting	ASC 280, “Disclosures About Segments of an Enterprise and Related Information,” requires that a public enterprise report financial and descriptive information about its reportable operating segments subject to certain aggregation criteria and quantitative thresholds. Operating segments are defined by ASC 280 as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision-makers in deciding how to allocate resources and in assessing performance.
		2014				2013			2012
	Revenue:
	Automotive Products
	United States	$	444,921,897			$	400,654,021		$	382,308,501
	Germany	262,505,346				244,949,664			239,081,723
	Japan	133,758,799				123,884,470			100,422,507
	Other	498,936,232				374,499,972			355,160,210
	Other	35,378,885				27,876,044			22,586,580
	Total	$	1,375,501,159			$	1,171,864,171		$	1,099,559,521
	Income (Loss) from Operations:
	Automotive Products	$	386,762,986			$	298,465,299		$	231,713,972
	Other	12,071,188				6,276,514			2,741,260
	Total	$	398,834,174			$	304,741,813		$	234,455,232
	Assets:
	Automotive Products	$	1,333,615,389			$	1,290,801,674		$	619,337,527
	Other	8,841,958				9,001,278			8,010,779
	Corporate	680,082,682				464,285,482			638,343,029
	Total	$	2,022,540,029			$	1,764,088,434		$	1,265,691,335
	Depreciation & Amortization:
	Automotive Products	$	75,320,999			$	58,723,222		$	47,976,800
	Other	321,426				316,836			317,534
	Corporate	1,733,880				3,814,097			1,885,489
	Total	$	77,376,305			$	62,854,155		$	50,179,823
	Capital Expenditures:
	Automotive Products	$	71,032,115			$	54,020,792		$	113,611,526
	Other	145,704				301,697			228,635
	Corporate	1,341,168				1,057,968			3,634,288
	Total	$	72,518,987			$	55,380,457		$	117,474,449
Schedule of Automotive Customers Individually Accounted For 10% or More of Net Sales	In 2014, the Company had four automotive customers (includes direct sales to OEM customers and sales through their Tier 1 suppliers), which individually accounted for 10% or more of net sales as follows:
		Toyota Motor Corporation		VW/Audi			Hyundai/Kia		Daimler AG		General Motors		FCA Group
	2014	12	%	14	%		#		10	%	#		11	%
	2013	13	%	14	%		#		11	%	#		#
	2012	14	%	14	%		11	%	11	%	10	%	#
	# - Less than 10 percent.

Quarterly_Financial_Informatio1

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table sets forth selected financial information for all of the quarters during the years ended December 31, 2014 and 2013 (in thousands, except per share data):
		First				Second				Third				Fourth
		2014		2013		2014		2013		2014		2013		2014		2013
	Net Sales	$	335,739	$	269,499	$	338,437	$	286,974	$	350,914	$	288,622	$	350,411	$	326,770
	Gross Profit	131,299		93,464		134,292		102,613		138,626		105,962		134,673		128,694
	Operating Income	97,178		63,854		99,835		71,596		103,206		73,656		98,615		95,636
	Net Income	68,566		45,431		76,727		52,097		72,337		55,521		70,975		69,881
	Earnings Per Share (Diluted)	$	0.24	$	0.16	$	0.26	$	0.18	$	0.25	$	0.19	$	0.24	$	0.24
	Earnings Per Share (Basic)	$	0.24	$	0.16	$	0.27	$	0.18	$	0.25	$	0.2	$	0.24	$	0.24

Comprehensive_Income_Tables

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Comprehensive Income [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Comprehensive income reflects the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. For the Company, comprehensive income represents net income adjusted for unrealized gains and losses on certain investments, foreign currency translation adjustments, and unrealized movement in derivative financial instruments designated as hedges.
		For the Twelve Months ended December 31,
		2014				2013				2012
	Foreign currency translation adjustments:
	Balance at beginning of period	$	2,507,922			$	2,458,933			$	2,129,957
	Other comprehensive income before reclassifications	(1,104,023		)		48,989				328,976
	Amounts reclassified from accumulated other comprehensive income	—				—				—
	Net current-period change	(1,104,023		)		48,989				328,976
	Balance at end of period	1,403,899				2,507,922				2,458,933
	Unrealized gains(losses) on available-for-sale securities:
	Balance at beginning of period	19,467,441				15,111,778				10,412,246
	Other comprehensive income before reclassifications	1,536,416				16,139,845				10,138,902
	Amounts reclassified from accumulated other comprehensive income	(10,135,535		)		(11,784,182		)		(5,439,370		)
	Net current-period change	(8,599,119		)		4,355,663				4,699,532
	Balance at end of period	10,868,322				19,467,441				15,111,778
	Unrealized gains (losses) on derivatives:
	Balance at beginning of period	—				—				—
	Other comprehensive income before reclassifications	(959,206		)		—				—
	Amounts reclassified from accumulated other comprehensive income	—				—				—
	Net current-period change	(959,206		)		—				—
	Balance at end of period	(959,206		)		—				—
	Accumulated other comprehensive income, end of period	$	11,313,015			$	21,975,363			$	17,570,711
	All amounts are shown net of tax. Amounts in parentheses indicate debits.
Reclassification out of Accumulated Other Comprehensive Income	The following table presents details of reclassifications out of other comprehensive income for the twelve months ended December 31, 2014, 2013 and 2012.
	Details about Accumulated Other Comprehensive Income Components		Amounts Reclassified from Other Comprehensive Income											Affected Line item in the Statement of Consolidated Income
			For the Twelve Months ended December 31,
			2014				2013				2012
	Unrealized gains and (losses) on available-for-sale securities
	Realized gain (loss) on sale of securities		$	15,593,131			$	18,129,511			$	8,368,261		Other, net
	Provision for Income Taxes		(5,457,596		)		(6,345,329		)		(2,928,891		)	Provision for Income Taxes
	Total reclassifications for the period		$	10,135,535			$	11,784,182			$	5,439,370		Net of tax

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The carrying value of Goodwill as of December 31, 2014 and December 31, 2013 was $307.4 million as set forth in the table below.
		Carrying Amount
	Balance as of December 31, 2013	$	307,365,845
	Acquisitions	—
	Divestitures	—
	Impairments	—
	Other	—
	Balance as of December 31, 2014	$	307,365,845
Schedule of Intangible Assets	The Intangible assets and related change in carrying values are set forth in the table belows as of December 31, 2014 and December 31, 2013.
	Other Intangible Assets	Gross		Accumulated Amortization			Net		Assumed Useful Life
	HomeLink®Trade Names and Trademarks	$	52,000,000	$	—		$	52,000,000	Indefinite
	HomeLink® Technology	180,000,000		(18,750,000		)	$	161,250,000	12 years
	Existing Customer Platforms	43,000,000		(5,375,000		)	$	37,625,000	10 years
	Exclusive Licensing Agreement	96,000,000		—			$	96,000,000	Indefinite
	Total other identifiable intangible assets	371,000,000		(24,125,000		)	346,875,000
	As of December 31, 2013:
	Other Intangible Assets	Gross		Accumulated Amortization			Net		Assumed Useful Life
	HomeLink®Trade Names and Trademarks	$	52,000,000	$	—		$	52,000,000	Indefinite
	HomeLink® Technology	180,000,000		(3,750,000		)	$	176,250,000	12 years
	Existing Customer Platforms	43,000,000		(1,075,000		)	$	41,925,000	10 years
	Exclusive Licensing Agreement	96,000,000		—			$	96,000,000	Indefinite
	Total other identifiable intangible assets	$	371,000,000	$	(4,825,000	)	$	366,175,000

Summary_of_Significant_Account3

Summary of Significant Accounting and Reporting Policies (Narrative) (Details) (USD $)	12 Months Ended			0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 05, 2014
Summary Of Significant Accounting And Reporting Policies [Line Items]
Allowance for obsolete and slow moving inventories	$6.70	$6.90
Depreciation expense	55.3	55	48.5
Advertising and promotional costs	1.1	0.4	1
Repair and maintenance of plant and equipment	$17.90	$14.90	$13.80
Shares related to stock plans not included in diluted average common shares outstanding because their effect would be antidilutive	1,228,694	6,754,622	6,665,438
Common Stocks
Summary Of Significant Accounting And Reporting Policies [Line Items]
Common stock split conversion ratio				2
Common stock split, stock dividend percent				100.00%
Buildings and improvements | Minimum
Summary Of Significant Accounting And Reporting Policies [Line Items]
Minimum estimated useful life, in years	7 years
Buildings and improvements | Maximum
Summary Of Significant Accounting And Reporting Policies [Line Items]
Minimum estimated useful life, in years	30 years
Machinery and equipment | Minimum
Summary Of Significant Accounting And Reporting Policies [Line Items]
Minimum estimated useful life, in years	3 years
Machinery and equipment | Maximum
Summary Of Significant Accounting And Reporting Policies [Line Items]
Minimum estimated useful life, in years	10 years

Summary_of_Significant_Account4

Summary of Significant Accounting and Reporting Policies (Schedule Of Allowance For Doubtful Accounts) (Details) (Allowance for Doubtful Accounts, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts
Activity in the Companybs allowance for doubtful accounts
Beginning Balance	$3,202,388	$3,400,000	$3,400,000
Net Additions/ (Reductions) to Costs and Expenses	-300,000	0	-577
Deductions and Other Adjustments	-191,140	-197,612	577
Ending Balance	$2,711,248	$3,202,388	$3,400,000

Summary_of_Significant_Account5

Summary of Significant Accounting and Reporting Policies (Schedule of Assets or Liabilities Having Recurring Measurements) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	$497,429,804	$309,591,724
Total	612,073,392	416,597,246
Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	0
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-Term Investments	1,021
Common Stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	24,648,451	33,282,439
Mutual Funds b Equity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	89,994,116	73,723,083
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	497,429,804	309,591,724
Total	612,073,392	416,597,246
Level 1 | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments
Level 1 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-Term Investments	1,021
Level 1 | Common Stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	24,648,451	33,282,439
Level 1 | Mutual Funds b Equity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	89,994,116	73,723,083
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	0	0
Total	0	0
Level 2 | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments
Level 2 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-Term Investments
Level 2 | Common Stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	0	0
Level 2 | Mutual Funds b Equity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	0	0
Level 3 | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments
Level 3 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-Term Investments
Level 3 | Common Stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	0	0
Level 3 | Mutual Funds b Equity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Investments	$0	$0

Summary_of_Significant_Account6

Summary of Significant Accounting and Reporting Policies (Schedule of Amortized Cost, Unrealized Gains And Losses, And Market Value Of Investment Securities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cost	$97,923,092	$77,055,612
Gross Unrealized Gains	17,855,921	29,998,513
Gross Unrealized Losses	-1,135,425	-48,603
Market Value	114,643,588	107,005,522
Other
Schedule of Available-for-sale Securities [Line Items]
Cost	1,021
Market Value	1,021
Common Stocks
Schedule of Available-for-sale Securities [Line Items]
Cost	17,069,742	22,799,035
Gross Unrealized Gains	7,933,717	10,532,007
Gross Unrealized Losses	-355,008	-48,603
Market Value	24,648,451	33,282,439
Mutual Funds b Equity
Schedule of Available-for-sale Securities [Line Items]
Cost	80,852,329	54,256,577
Gross Unrealized Gains	9,922,204	19,466,506
Gross Unrealized Losses	-780,417	0
Market Value	$89,994,116	$73,723,083

Summary_of_Significant_Account7

Summary of Significant Accounting and Reporting Policies (Schedule of Unrealized Losses on Investments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Aggregate Unrealized Losses, Less than one year	$1,135,425	$48,603
Continuous unrealized loss position, Aggregate Fair Value	$19,972,258	$1,886,080

Summary_of_Significant_Account8

Summary of Significant Accounting and Reporting Policies (Schedule of Inventories) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Raw materials	$90,780,320	$75,081,810
Work-in-process	24,135,944	21,409,976
Finished goods	26,841,620	23,582,378
Total Inventory	$141,757,884	$120,074,164

Summary_of_Significant_Account9

Summary of Significant Accounting and Reporting Policies (Schedule of Earnings Per Share, Basic And Diluted) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerators:
Numerator for both basic and diluted EPS, net income	$70,975,000	$72,337,000	$76,727,000	$68,566,000	$69,881,000	$55,521,000	$52,097,000	$45,431,000	$288,604,579	$222,929,949	$168,586,840
Denominators:
Denominator for basic EPS, weighted-average common shares outstanding									290,952,123	286,920,036	286,195,060
Potentially dilutive shares resulting from stock option plans									3,347,236	1,628,306	1,741,002
Denominator for diluted EPS									294,299,359	288,548,342	287,936,062

Debt_and_Financing_Arrangement2

Debt and Financing Arrangements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Oct. 01, 2014	Dec. 31, 2012	Sep. 27, 2013
Debt Instrument [Line Items]
Amount outstanding	$258,125,000	$265,625,000
Financial Liabilities:
Effect of 1% increase on borrowing rate to interest expense	2,500,000
Interest Rate Swap
Debt Instrument [Line Items]
Amount of hedged item			150,000,000
Interest rate of derivative			1.89%
Notional amount of derivative liability	150,000,000	0	150,000,000	0
Interest Rate Swap | Level 2
Financial assets:
Interest Rate Swap Asset	0	0		0
Financial Liabilities:
Interest Rate Swap Liability (Other Accrued Liabilities)	1,475,702	0		0
Other, net
Debt Instrument [Line Items]
Payments of financing charges	3,500,000	900,000
LIBOR Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.17%
Term Loan and Revolving Facility
Debt Instrument [Line Items]
Extinguishment of debt amount	7,500,000	1,900,000
Credit Agreement
Debt Instrument [Line Items]
Additional principal amount available					75,000,000
Revolving Facility
Debt Instrument [Line Items]
Principal amount					150,000,000
Amount outstanding	125,000,000
Available borrowing capacity	25,000,000
Term Loan
Debt Instrument [Line Items]
Principal amount					150,000,000
Amount outstanding	140,600,000
Annual principal repayments amount	7,500,000
Swing Loans
Debt Instrument [Line Items]
Additional principal amount available					20,000,000
Letters of Credit
Debt Instrument [Line Items]
Additional principal amount available					$20,000,000

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefits accrued interest	$821,000	$555,000
Tax benefits associated with the exercise, vesting or disposition of stock under stock plans recognized as an adjustment of additional paid-in capital	10,800,000	7,400,000	1,500,000
Income taxes paid	$128,800,000	$97,100,000	$63,400,000

Income_Taxes_Schedule_Of_Recon

Income Taxes (Schedule Of Reconciliation Of Beginning And Ending Amount Of Unrecognized Tax Benefits ) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Beginning of year	$7,351,000	$4,168,000	$2,476,000
Additions based on tax positions related to the current year	1,328,000	1,595,000	785,000
Additions for tax positions in prior years	634,000	1,633,000	907,000
Reductions for tax positions in prior years	-676,000	-45,000	0
Reductions as a result of a lapse of the applicable statute of limitations	-349,000	0	0
End of year	$8,288,000	$7,351,000	$4,168,000

Income_Taxes_Schedule_Of_Compo

Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Currently payable:
Federal	$108,689,911	$95,285,094	$76,507,760
State	2,236,000	3,259,000	2,450,000
Foreign	978,000	1,353,000	1,238,000
Total	111,903,911	99,897,094	80,195,760
Net deferred:
Primarily federal	14,818,000	5,237,000	843,000
Provision for income taxes	$126,721,911	$105,134,094	$81,038,760

Income_Taxes_Schedule_Of_Effec

Income Taxes (Schedule Of Effective Income Tax Rates Different From Statutory Federal Income Tax Rates) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit	0.30%	0.60%	0.60%
Domestic production exclusion	-2.60%	-3.10%	-2.90%
Research tax credit (1)	-2.00%	-0.40%	0.00%
Other	-0.20%	-0.10%	-0.20%
Effective income tax rate	30.50%	32.00%	32.50%
Reductions related to prior tax year amended tax filings	1.30%

Income_Taxes_Schedule_Of_Defer

Income Taxes (Schedule Of Deferred Income Tax Assets And Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Current
Assets:
Accruals not currently deductible	$2,605,711	$2,970,671
Stock based compensation	13,508,845	13,290,429
Impairment loss on available-for-sale securities	0	0
Intangible Assets	0	0
Other	4,440,407	4,713,241
Total deferred income tax assets	20,554,963	20,974,341
Liabilities:
Excess tax over book depreciation	0	0
Goodwill	0	0
Unrealized gain on investments	0	0
Intangible assets	0	0
Other	-1,117,956	-558,249
Net deferred income taxes	19,437,007	20,416,092
Non-Current
Assets:
Accruals not currently deductible	224,803	182,803
Stock based compensation	2,508,304	2,202,940
Impairment loss on available-for-sale securities	135,724	175,091
Intangible Assets	0	169,913
Other	19,765	40,203
Total deferred income tax assets	2,888,596	2,770,950
Liabilities:
Excess tax over book depreciation	-46,017,949	-41,374,851
Goodwill	-8,868,168	-1,792,968
Unrealized gain on investments	-6,368,670	-10,482,468
Intangible assets	-1,205,230	0
Other
Net deferred income taxes	($59,571,421)	($50,879,337)

Employee_Benefit_Plan_Details

Employee Benefit Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Company's contributions under 401(k) retirement savings plan	$5.10	$2.80	$2.50

StockBased_Compensation_Plans_1

Stock-Based Compensation Plans (Details) (USD $)	12 Months Ended			36 Months Ended	0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 05, 2014	31-May-14	Dec. 31, 2008	Dec. 31, 2003
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares sold to employees during period	137,028	155,264	204,996
Shares granted with restriction period	431,880	374,180	451,460
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options available for grant						24,000,000
Options granted net of shares from canceled/expired options	5,255,536
Unrecognized compensation cost	27,959,369			27,959,369
Weighted-average period for unrecognized compensation cost expected to be recognized	2 years 1 month 6 days
Non-Employee Director Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted net of shares from canceled/expired options				1,086,480
Option vesting period	6 months
Shares approved			1,000,000
Option expiration period, years	10 years
Previous Non-Employee Director Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted net of shares from canceled/expired options				266,000
Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved							4,000,000
Restricted period, maximum, in years	10 years
Shares granted with restriction period	1,577,580
Restricted period for granted shares, in years	5 years
Unearned stock-based compensation	12,327,280			12,327,280
Amortization expense	3,095,136	2,760,446	2,108,583
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved								2,000,000
ESPP discount rate	85.00%
Discount recognized as compensation expense		15.00%
Employee Stock Purchase Plan, 2003
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares sold to employees during period	0	52,340	204,996
Cumulative shares sold to employees during period	2,400,000			2,400,000
Weighted average fair value of shares sold	8.51			8.51
Employee Stock Purchase Plan, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares sold to employees during period	137,028	102,924	0
Cumulative shares sold to employees during period	239,952			239,952
Weighted average fair value of shares sold	12.99			12.99
Minimum | Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period	1 year
Award expiration period	5 years
Minimum | Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market price	13.39	10.12	8.64
Maximum | Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period	5 years
Award expiration period	7 years
Maximum | Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market price	18.31	16.42	12.23
Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans	4			4
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans	2			2
Common Stocks
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock split conversion ratio					2
Common stock split, stock dividend percent					100.00%

StockBased_Compensation_Plans_2

Stock-Based Compensation Plans (Schedule of Weighted-Average Assumptions) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	2.30%	2.60%	2.70%
Expected volatility	38.50%	44.70%	45.50%
Risk-free interest rate	1.70%	1.30%	0.80%
Expected term of options (in years)	4 years 2 months 0 days	4 years 0 months 0 days	4 years 1 month 6 days
Weighted-average grant-date fair value	$4	$4	$3
Non-Employee Director Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	2.20%	2.70%	2.60%
Expected volatility	39.60%	45.90%	44.50%
Risk-free interest rate	2.50%	1.90%	1.70%
Expected term of options (in years)	6 years 5 months 0 days	7 years 0 months 0 days	6 years 9 months 18 days
Weighted-average grant-date fair value	$5	$5	$4

StockBased_Compensation_Plans_3

Stock-Based Compensation Plans (Summary of Stock Option Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding at Beginning of Year	18,000	17,722	15,110
Shares, Granted	5,757	5,462	5,282
Shares, Exercised	-5,224	-4,450	-1,378
Shares, Forfeited	-704	-734	-1,292
Shares, Outstanding at End of Year	17,829	18,000	17,722
Shares, Exercisable at End of Year	4,564	5,490	6,006
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Wtd. Avg. Ex. Price, Outstanding at Beginning of Year (usd per share)	$12	$11	$11
Wtd. Avg. Ex. Price, Granted (usd per share)	$15	$13	$10
Wtd. Avg. Ex. Price, Exercised (usd per share)	$11	$8	$8
Wtd. Avg. Ex. Price, Forfeited (usd per share)	$13	$12	$11
Wtd. Avg. Ex. Price, Outstanding at End of Year (usd per share)	$13	$12	$11
Wtd. Avg. Ex. Price, Exercisable at End of Year (usd per share)	$12	$12	$10
Wtd. Avg. Remaining Contract Life, Outstanding at End of Year	3 years 6 months	3 years 4 months 24 days	3 years 4 months 24 days
Wtd. Avg. Remaining Contract Life, Exercisable at End of Year	2 years 3 months 18 days	2 years 3 months 18 days	2 years 2 months 12 days
Aggregate Intrinsic Value, Exercised	$26,618	$20,884	$3,810
Aggregate Intrinsic Value, Outstanding at End of Year	90,759	85,633	11,730
Aggregate Intrinsic Value, Exercisable at End of Year	28,342	28,302	7,617
Non-Employee Director Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding at Beginning of Year	462	468	384
Shares, Granted	98	84	84
Shares, Exercised	-167	-90	0
Shares, Forfeited	-12	0	0
Shares, Outstanding at End of Year	381	462	468
Shares, Exercisable at End of Year	381	462	468
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Wtd. Avg. Ex. Price, Outstanding at Beginning of Year (usd per share)	$11	$11	$11
Wtd. Avg. Ex. Price, Granted (usd per share)	$14	$12	$11
Wtd. Avg. Ex. Price, Exercised (usd per share)	$10	$10	$0
Wtd. Avg. Ex. Price, Forfeited (usd per share)	$16	$0	$0
Wtd. Avg. Ex. Price, Outstanding at End of Year (usd per share)	$12	$11	$11
Wtd. Avg. Ex. Price, Exercisable at End of Year (usd per share)	$12	$11	$11
Wtd. Avg. Remaining Contract Life, Outstanding at End of Year	6 years 8 months 12 days	6 years 4 months 24 days	6 years 4 months 24 days
Wtd. Avg. Remaining Contract Life, Exercisable at End of Year	6 years 8 months 12 days	6 years 4 months 24 days	6 years 4 months 24 days
Aggregate Intrinsic Value, Exercised	893	300
Aggregate Intrinsic Value, Outstanding at End of Year	2,137	2,491	225
Aggregate Intrinsic Value, Exercisable at End of Year	$2,137	$2,491	$225

StockBased_Compensation_Plans_4

Stock-Based Compensation Plans (Schedule of Non-Vested Stock Option Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Nonvested stock options at Beginning of Year	12,508	11,716	11,060
Shares, Granted	5,757	5,462	5,282
Shares, Vested	-4,346	-4,044	-3,872
Shares, Forfeited	-654	-626	-754
Shares, Nonvested stock options at End of Year	13,265	12,508	11,716
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Wtd. Avg Grant Date Fair Value, Nonvested stock options at Beginning of Year (usd per share)	$4	$3	$3
Wtd. Avg Grant Date Fair Value, Granted (usd per share)	$4	$4	$3
Wtd. Avg Grant Date Fair Value, Vested (usd per share)	$3	$3	$3
Wtd. Avg Grant Date Fair Value, Forfeited (usd per share)	$4	$4	$3
Wtd. Avg Grant Date Fair Value, Nonvested stock options at End of Year (usd per share)	$4	$4	$3
Non-Employee Director Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, Nonvested stock options at Beginning of Year	0	0	0
Shares, Granted	98	84	84
Shares, Vested	-98	-84	-84
Shares, Forfeited	0	0	0
Shares, Nonvested stock options at End of Year	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Wtd. Avg Grant Date Fair Value, Nonvested stock options at Beginning of Year (usd per share)	$0	$0	$0
Wtd. Avg Grant Date Fair Value, Granted (usd per share)	$5	$5	$4
Wtd. Avg Grant Date Fair Value, Vested (usd per share)	$5	$5	$4
Wtd. Avg Grant Date Fair Value, Forfeited (usd per share)	$0	$0	$0
Wtd. Avg Grant Date Fair Value, Nonvested stock options at End of Year (usd per share)	$0	$0	$0

Contingencies_Details

Contingencies (Details) (Litigation Settled [Member])	0 Months Ended
	Jun. 25, 2012	Oct. 05, 2012	Jul. 27, 2012
	co-defendant	complaint	complaint
	complaint
Loss Contingencies [Line Items]
Number of complaints filed	4
Number of co-defendants	1
Total number of customers cited as possible co-defendants	2
Number of complaints served			4
Number of complains answered		4
SmartBeam [Member]
Loss Contingencies [Line Items]
Number of complaints filed	2
Number of patents infringed upon	1
Monitoring System Products [Member]
Loss Contingencies [Line Items]
Number of complaints filed	2
Number of patents infringed upon	2

Segment_Reporting_Schedule_of_

Segment Reporting (Schedule of Automotive and Other Segment Reporting) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$350,411,000	$350,914,000	$338,437,000	$335,739,000	$326,770,000	$288,622,000	$286,974,000	$269,499,000	$1,375,501,159	$1,171,864,171	$1,099,559,521
Income (Loss) from Operations	98,615,000	103,206,000	99,835,000	97,178,000	95,636,000	73,656,000	71,596,000	63,854,000	398,834,174	304,741,813	234,455,232
Assets	2,022,540,029				1,764,088,434				2,022,540,029	1,764,088,434	1,265,691,335
Depreciation & Amortization									77,376,305	62,854,155	50,179,823
Capital Expenditures									72,518,987	55,380,457	117,474,449
Automotive Products
Segment Reporting Information [Line Items]
Income (Loss) from Operations									386,762,986	298,465,299	231,713,972
Assets	1,333,615,389				1,290,801,674				1,333,615,389	1,290,801,674	619,337,527
Depreciation & Amortization									75,320,999	58,723,222	47,976,800
Capital Expenditures									71,032,115	54,020,792	113,611,526
Other
Segment Reporting Information [Line Items]
Revenues									35,378,885	27,876,044	22,586,580
Income (Loss) from Operations									12,071,188	6,276,514	2,741,260
Assets	8,841,958				9,001,278				8,841,958	9,001,278	8,010,779
Depreciation & Amortization									321,426	316,836	317,534
Capital Expenditures									145,704	301,697	228,635
Corporate
Segment Reporting Information [Line Items]
Assets	680,082,682				464,285,482				680,082,682	464,285,482	638,343,029
Depreciation & Amortization									1,733,880	3,814,097	1,885,489
Capital Expenditures									1,341,168	1,057,968	3,634,288
United States | Automotive Products
Segment Reporting Information [Line Items]
Revenues									444,921,897	400,654,021	382,308,501
Germany | Automotive Products
Segment Reporting Information [Line Items]
Revenues									262,505,346	244,949,664	239,081,723
Japan | Automotive Products
Segment Reporting Information [Line Items]
Revenues									133,758,799	123,884,470	100,422,507
Other | Automotive Products
Segment Reporting Information [Line Items]
Revenues									$498,936,232	$374,499,972	$355,160,210

Segment_Reporting_Schedule_of_1

Segment Reporting (Schedule of Automotive Customers Individually Accounted For 10% or More of Net Sales) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue, Major Customer [Line Items]
Percentage net sales invoiced and paid in foreign currencies	6.00%	7.00%	8.00%
Number of customers which individually accounted for 10% or more of net sales	4
Percentage of net sales five automotive customers individually accounted for	10.00%
Customer concentration risk | Toyota Motor Corporation
Revenue, Major Customer [Line Items]
Percentage of revenue individually accounted by customers (less than 10% in 2014 and 2013 for Hyundai/Kia and General Motors and less than 10% for FCA Group in 2013 and 2012)	12.00%	13.00%	14.00%
Customer concentration risk | VW/Audi
Revenue, Major Customer [Line Items]
Percentage of revenue individually accounted by customers (less than 10% in 2014 and 2013 for Hyundai/Kia and General Motors and less than 10% for FCA Group in 2013 and 2012)	14.00%	14.00%	14.00%
Customer concentration risk | Hyundai/Kia
Revenue, Major Customer [Line Items]
Percentage of revenue individually accounted by customers (less than 10% in 2014 and 2013 for Hyundai/Kia and General Motors and less than 10% for FCA Group in 2013 and 2012)	10.00%	10.00%	11.00%
Customer concentration risk | Daimler AG
Revenue, Major Customer [Line Items]
Percentage of revenue individually accounted by customers (less than 10% in 2014 and 2013 for Hyundai/Kia and General Motors and less than 10% for FCA Group in 2013 and 2012)	10.00%	11.00%	11.00%
Customer concentration risk | General Motors
Revenue, Major Customer [Line Items]
Percentage of revenue individually accounted by customers (less than 10% in 2014 and 2013 for Hyundai/Kia and General Motors and less than 10% for FCA Group in 2013 and 2012)	10.00%	10.00%	10.00%
Customer concentration risk | FCA Group [Member]
Revenue, Major Customer [Line Items]
Percentage of revenue individually accounted by customers (less than 10% in 2014 and 2013 for Hyundai/Kia and General Motors and less than 10% for FCA Group in 2013 and 2012)	11.00%	10.00%	10.00%

Quarterly_Financial_Informatio2

Quarterly Financial Information (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net Sales	$350,411,000	$350,914,000	$338,437,000	$335,739,000	$326,770,000	$288,622,000	$286,974,000	$269,499,000	$1,375,501,159	$1,171,864,171	$1,099,559,521
Gross Profit	134,673,000	138,626,000	134,292,000	131,299,000	128,694,000	105,962,000	102,613,000	93,464,000	538,889,695	430,732,902	372,818,559
Operating Income	98,615,000	103,206,000	99,835,000	97,178,000	95,636,000	73,656,000	71,596,000	63,854,000	398,834,174	304,741,813	234,455,232
Net Income	$70,975,000	$72,337,000	$76,727,000	$68,566,000	$69,881,000	$55,521,000	$52,097,000	$45,431,000	$288,604,579	$222,929,949	$168,586,840
Earnings Per Share (Diluted) (in dollars per share)	$0.24	$0.25	$0.26	$0.24	$0.24	$0.19	$0.18	$0.16	$0.98	$0.77	$0.59
Earnings Per Share (Basic) (in dollars per share)	$0.24	$0.25	$0.27	$0.24	$0.24	$0.20	$0.18	$0.16	$0.99	$0.78	$0.59

Comprehensive_Income_AOCI_Roll

Comprehensive Income (AOCI Rollforward) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	$21,975,363	$17,570,711
Comprehensive Income	277,942,231	227,334,601	173,615,348
Balance at end of period	11,313,015	21,975,363	17,570,711
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	2,507,922	2,458,933	2,129,957
Other comprehensive income before reclassifications	-1,104,023	48,989	328,976
Amounts reclassified from accumulated other comprehensive income	0	0	0
Comprehensive Income	-1,104,023	48,989	328,976
Balance at end of period	1,403,899	2,507,922	2,458,933
Unrealized gains(losses) on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	19,467,441	15,111,778	10,412,246
Other comprehensive income before reclassifications	1,536,416	16,139,845	10,138,902
Amounts reclassified from accumulated other comprehensive income	-10,135,535	-11,784,182	-5,439,370
Comprehensive Income	-8,599,119	4,355,663	4,699,532
Balance at end of period	10,868,322	19,467,441	15,111,778
Unrealized gains (losses) on derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	0	0	0
Other comprehensive income before reclassifications	-959,206	0	0
Amounts reclassified from accumulated other comprehensive income	0	0	0
Comprehensive Income	-959,206	0	0
Balance at end of period	($959,206)	$0	$0

Comprehensive_Income_Reclassif

Comprehensive Income (Reclassification Out of Accumulated Other Comprehensive Income) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	($126,721,911)	($105,134,094)	($81,038,760)
Amounts Reclassified from Other Comprehensive Income | Unrealized gains and (losses) on available-for-sale securities
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized gain (loss) on sale of securities	15,593,131	18,129,511	8,368,261
Provision for Income Taxes	-5,457,596	-6,345,329	-2,928,891
Total reclassifications for the period	$10,135,535	$11,784,182	$5,439,370

Business_Combinations_Details

Business Combinations (Details) (HomeLinkB., USD $)	0 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013
HomeLinkB.
Business Acquisition [Line Items]
Purchase price	$700
Cash paid to acquire business	$423

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 27, 2013
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	$307,365,845	$307,365,845
Percentage of fair value in excess of carrying amount for automotive reporting unit	248.00%
Amortization expense	22,000,000	7,900,000	1,700,000
Patents and Other Intangible Assets [Member]
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	10 years
Accumulated amortization	35,200,000	13,400,000
Amortization expense, 2015	22,000,000
Amortization expense, 2016	22,000,000
Amortization expense, 2017	22,000,000
Amortization expense, 2018	22,000,000
Amortization expense, 2019	22,000,000
HomeLinkB.
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	307,365,845			337,600,000
Accumulated amortization	$24,125,000	$4,825,000

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Goodwill [Roll Forward]
Balance as of December 31, 2013	$307,365,845
Acquisitions	0
Divestitures	0
Impairments	0
Other	0
Balance as of December 31, 2014	$307,365,845

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets (Schedule of Intangible Assets) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Intangible assets, net	$346,875,000	$366,175,000
HomeLinkB.
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, accumulated amortization	-24,125,000	-4,825,000
Intangible assets, gross	371,000,000	371,000,000
Intangible assets, net	346,875,000	366,175,000
HomeLinkB. | Homelink Technology
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	180,000,000	180,000,000
Finite-lived intangible assets, accumulated amortization	-18,750,000	-3,750,000
Finite-lived intangible assets, net	161,250,000	176,250,000
Finite-lived intangible asset, useful life	12 years	12 years
HomeLinkB. | Existing Customer Platforms
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	43,000,000	43,000,000
Finite-lived intangible assets, accumulated amortization	-5,375,000	-1,075,000
Finite-lived intangible assets, net	37,625,000	41,925,000
Finite-lived intangible asset, useful life	10 years	10 years
HomeLinkB. | HomeLink Trade Names and Trademarks
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	52,000,000	52,000,000
HomeLinkB. | Exclusive Licensing Agreement
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$96,000,000	$96,000,000

Stock_Split_Details

Stock Split (Details)	0 Months Ended
	Dec. 05, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 17, 2014
Class of Stock [Line Items]
Common stock, shares outstanding (in shares)		295,247,958	291,156,046
Common Stocks
Class of Stock [Line Items]
Common stock split conversion ratio	2
Common stock split, stock dividend percent	100.00%
Common stock split, additional shares issued for every share held (in shares)				1
Common stock, shares outstanding (in shares)		295,200,000		147,600,000