Gentex (GNTX) 10-Q 1 Nov 24 2024 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2024	Oct. 25, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	0-10235
Entity Registrant Name	GENTEX CORPORATION
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-2030505
Entity Address, Address Line One	600 N. Centennial
Entity Address, City or Town	Zeeland
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	49464
City Area Code	616
Local Phone Number	772-1800
Title of 12(b) Security	Common Stock, par value $0.06 per share
Trading Symbol	GNTX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		227,431,688
Entity Central Index Key	0000355811
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Sep. 30, 2024	Dec. 31, 2023	[1]
CURRENT ASSETS
Cash and cash equivalents	$ 179,639,743	$ 226,435,019
Short-term investments	20,462,581	14,356,476
Accounts receivable, net	356,338,008	321,809,868
Inventories, net	449,311,020	402,473,028
Prepaid expenses and other	39,932,866	32,663,762
Total current assets	1,045,684,218	997,738,153
PLANT AND EQUIPMENT—NET	703,583,489	652,877,672
OTHER ASSETS
Goodwill	340,105,631	340,105,631
Long-term investments	325,561,578	299,080,876
Intangible assets, net	201,604,035	214,005,910
Deferred tax asset	50,192,359	41,113,759
Patents and other assets, net	68,565,533	66,515,551
Total other assets	986,029,136	960,821,727
Total assets	2,735,296,843	2,611,437,552
CURRENT LIABILITIES
Accounts payable	182,606,296	184,398,820
Accrued liabilities	100,558,357	87,210,156
Total current liabilities	283,164,653	271,608,976
OTHER NON-CURRENT LIABILITIES	34,504,848	27,311,507
Total liabilities	317,669,501	298,920,483
SHAREHOLDERS’ INVESTMENT
Common stock	13,646,597	13,887,326
Additional paid-in capital	1,000,948,512	968,245,875
Retained earnings	1,405,918,157	1,336,940,990
Accumulated other comprehensive loss	(2,885,924)	(6,557,122)
Total shareholders’ investment	2,417,627,342	2,312,517,069
Total liabilities and shareholders’ investment	$ 2,735,296,843	$ 2,611,437,552
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

UNAUDITED CONDENSED CONSOLIDA_2

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
NET SALES		$ 608,525,777	$ 575,848,490	$ 1,771,676,766	$ 1,710,082,647
COST OF GOODS SOLD		404,462,142	384,407,857	1,176,812,215	1,150,821,744
Gross profit		204,063,635	191,440,633	594,864,551	559,260,903
OPERATING EXPENSES:
Engineering, research and development		48,225,968	40,197,517	134,411,948	112,825,054
Selling, general & administrative		30,109,515	28,826,587	90,494,117	83,479,285
Total operating expenses		78,335,483	69,024,104	224,906,065	196,304,339
Income from operations		125,728,152	122,416,529	369,958,486	362,956,564
OTHER INCOME
Investment income, net		18,982,629	3,851,967	3,220,333	9,682,096
Other income (loss), net		744,569	(1,788,335)	1,255,438	(3,559,613)
Total other income		19,727,198	2,063,632	4,475,771	6,122,483
INCOME BEFORE PROVISION FOR INCOME TAXES		145,455,350	124,480,161	374,434,257	369,079,047
PROVISION FOR INCOME TAXES		22,906,309	19,754,749	57,614,063	57,619,971
NET INCOME		$ 122,549,041	$ 104,725,412	$ 316,820,194	$ 311,459,076
EARNINGS PER SHARE:
Basic (in dollars per share)	[1]	$ 0.54	$ 0.45	$ 1.38	$ 1.33
Diluted (in dollars per share)	[1]	0.53	0.45	1.38	1.33
Cash Dividends Declared per Share (in dollars per share)		$ 0.12	$ 0.12	$ 0.36	$ 0.36
[1] (1) Earnings Per Share has been adjusted to exclude the portion of net income allocated to participating securities as a result of share-based payment awards.

UNAUDITED CONDENSED CONSOLIDA_3

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 122,549,041	$ 104,725,412	$ 316,820,194	$ 311,459,076
Other comprehensive (loss) income before tax:
Foreign currency translation adjustments	1,776,813	(717,457)	317,059	(2,295,001)
Unrealized gains on debt securities, net	4,193,565	363,905	4,245,746	3,500,247
Other comprehensive (loss) income, before tax	5,970,378	(353,552)	4,562,805	1,205,246
Income tax impact related to components of other comprehensive (loss) income	880,649	76,420	891,607	735,052
Other comprehensive (loss) income, net of tax	5,089,729	(429,972)	3,671,198	470,194
Comprehensive income	$ 127,638,770	$ 104,295,440	$ 320,491,392	$ 311,929,270

UNAUDITED CONDENSED CONSOLIDA_4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' INVESTMENT - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024		Sep. 30, 2023
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	$ 2,400,299,527	$ 2,195,949,326	$ 2,312,517,069	[1]	$ 2,065,792,821
Issuance of common stock from stock plan transactions (in shares)			1,800,000
Issuance of common stock from stock plan transactions	3,782,044	10,422,050	$ 24,024,353		24,304,861
Issuance of common stock related to acquisitions					0
Repurchases of common stock (in shares)			(5,800,000)
Repurchases of common stock	(96,339,949)	(25,169,378)	$ (187,678,611)		(78,735,501)
Stock-based compensation expense related to stock options, employee stock purchases and restricted stock	9,540,105	10,948,031	30,936,895		29,212,236
Dividends declared	(27,293,155)	(27,991,662)	(82,663,756)		(84,049,880)
Net income	122,549,041	104,725,412	316,820,194		311,459,076
Other comprehensive income (loss)	5,089,729	(429,972)	3,671,198		470,194
Balance at end of period	$ 2,417,627,342	$ 2,268,453,807	$ 2,417,627,342		$ 2,268,453,807
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period (in shares)	230,229,539	233,429,994	231,455,443		234,169,335
Balance at beginning of period	$ 13,813,772	$ 14,005,799	$ 13,887,326		$ 14,050,160
Issuance of common stock from stock plan transactions (in shares)	408,566	605,637	1,786,232		1,833,596
Issuance of common stock from stock plan transactions	$ 24,514	$ 36,338	$ 107,174		$ 110,016
Repurchases of common stock (in shares)	(3,194,815)	(776,488)	(5,798,385)		(2,743,788)
Repurchases of common stock	$ (191,689)	$ (46,589)	$ (347,903)		$ (164,628)
Balance at end of period (in shares)	227,443,290	233,259,143	227,443,290		233,259,143
Balance at end of period	$ 13,646,597	$ 13,995,548	$ 13,646,597		$ 13,995,548
Additional  Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	1,000,014,813	942,660,764	968,245,875		917,499,323
Issuance of common stock from stock plan transactions	3,757,530	10,385,712	23,917,179		24,194,845
Repurchases of common stock	(12,363,936)	(2,795,358)	(22,151,437)		(9,707,255)
Stock-based compensation expense related to stock options, employee stock purchases and restricted stock	9,540,105	10,948,031	30,936,895		29,212,236
Balance at end of period	1,000,948,512	961,199,149	1,000,948,512		961,199,149
Retained  Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	1,394,446,595	1,252,525,531	1,336,940,990		1,148,386,272
Repurchases of common stock	(83,784,324)	(22,327,431)	(165,179,271)		(68,863,618)
Dividends declared	(27,293,155)	(27,991,662)	(82,663,756)		(84,049,880)
Net income	122,549,041	104,725,412	316,820,194		311,459,076
Balance at end of period	1,405,918,157	1,306,931,850	1,405,918,157		1,306,931,850
Accumulated  Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(7,975,653)	(13,242,768)	(6,557,122)		(14,142,934)
Other comprehensive income (loss)	5,089,729	(429,972)	3,671,198		470,194
Balance at end of period	$ (2,885,924)	$ (13,672,740)	$ (2,885,924)		$ (13,672,740)
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

UNAUDITED CONDENSED CONSOLIDA_5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' INVESTMENT (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Stockholders' Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.12	$ 0.12	$ 0.36	$ 0.36

UNAUDITED CONDENSED CONSOLIDA_6

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 316,820,194	$ 311,459,076
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	70,887,294	71,001,177
(Gain) on disposal of assets	(1,279,049)	(271,510)
Loss on disposal of assets	48,618	250,435
(Gain) on sale of investments and technology investment income	(4,736,312)	(2,747,586)
Loss on sale of investments and technology investment losses	14,839,974	6,840,692
Deferred tax expense	(9,970,207)	(11,870,944)
Stock-based compensation expense related to employee stock options, employee stock purchases and restricted stock	30,936,895	29,212,236
Change in operating assets and liabilities:
Accounts receivable, net	(34,528,140)	(74,648,395)
Inventories	(46,837,992)	8,907,490
Prepaid expenses and other	(2,616,370)	(5,416,624)
Accounts payable	(8,976,998)	27,451,773
Accrued liabilities, excluding dividends declared	19,229,845	7,500,486
Net cash provided by operating activities	343,817,752	367,668,306
Activity in investments:
Sales proceeds	35,059,971	32,839,883
Maturities and calls	10,260,000	14,435,000
Purchases	(83,764,695)	(112,608,739)
Plant and equipment additions	(102,966,564)	(121,393,801)
Proceeds from sale of plant and equipment	142,400	185,610
Increase in other assets	(5,614,129)	(2,533,687)
Net cash used for investing activities	(146,883,017)	(189,075,734)
CASH FLOWS USED FOR FINANCING ACTIVITIES:
Issuance of common stock from stock plan transactions	24,024,353	24,304,861
Cash dividends paid	(83,145,216)	(84,159,105)
Repurchases of common stock	(184,609,148)	(76,859,341)
Net cash used for financing activities	(243,730,011)	(136,713,585)
NET INCREASE IN CASH AND CASH EQUIVALENTS	(46,795,276)	41,878,987
CASH, CASH EQUIVALENTS, and RESTRICTED CASH, beginning of period	226,435,019	218,754,638
CASH, CASH EQUIVALENTS, and RESTRICTED CASH, end of period	179,639,743	260,633,625
Non-cash investing and financing activities:
Change in property and equipment in accounts payable and accrued expenses and other current liabilities	$ (4,115,011)	$ 9,708,125

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The unaudited condensed consolidated financial statements included herein have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. It is suggested that these unaudited condensed consolidated financial statements be read in conjunction with the financial statements and notes thereto included in the Company's 2023 annual report on Form 10-K. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments, consisting of only a normal and recurring nature, necessary to present fairly the financial position of the Company as of September 30, 2024, and the results of operations and cash flows for the interim periods presented.

Adoption of New Accounting Stan

Adoption of New Accounting Standards	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Adoption of New Accounting Standards	Adoption of New Accounting Standards In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2023-07, Improvements to Reportable Segment Disclosures . This ASU updates reportable segment disclosure requirements by requiring disclosures of significant reportable segment expenses that are regularly provided to the Chief Operating Decision Maker (“CODM”) and included within each reported measure of a segment's profit or loss. This ASU also requires disclosure of the title and position of the individual identified as the CODM and an explanation of how the CODM uses the reported measures of a segment’s profit or loss in assessing segment performance and deciding how to allocate resources. The ASU is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Adoption of the ASU should be applied retrospectively to all prior periods presented in the financial statements. Early adoption is also permitted. The Company will likely include additional disclosures when this ASU is adopted by the Company. The Company is currently evaluating the provisions of this ASU and expects to adopt the ASU for the year ending December 31, 2024. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures . Under this ASU, public benefit entities must annually “(1) disclose specific categories in the rate reconciliation and (2) provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5 percent of the amount computed by multiplying pretax income (or loss) by the applicable statutory income tax rate).” This ASU is effective on a prospective basis for the Company in the fiscal year ending December 31, 2025. This ASU will result in additional disclosures being included in the consolidated financial statements once adopted.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the cost of an acquisition in excess of the fair values assigned to identifiable net assets acquired. The Company recorded Goodwill of: $307.4 million as part of the HomeLink ® acquisition in 2013; $3.7 million as part of the acquisition of Vaporsens, Inc. ("Vaporsens") in 2020; $0.2 million as part of the acquisition of Air-Craftglass Production BV ("Air-Craftglass") in 2020; $1.0 million as a part of the acquisition of Argil, Inc. ("Argil") in 2020; $2.0 million as part of the acquisition of Guardian Optical Technologies ("Guardian") in 2021; and $26.7 million as part of the acquisition of eSight in the fourth quarter of 2023. The carrying value of Goodwill as of both September 30, 2024 and December 31, 2023 was $340.1 million , as set forth in the table below: Carrying Amount Balance as of December 31, 2023 $ 340,105,631 Acquisitions — Divestitures — Impairments — Other — Balance as of September 30, 2024 $ 340,105,631 In addition to annual impairment testing, which is performed as of the first day of the fourth quarter, the Company continuously monitors for events and circumstances that could negatively impact the key assumptions in determining fair value of goodwill or other intangible assets thus resulting in the need for interim impairment 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 macroeconomic conditions. No such events or circumstances that might negatively impact the key assumptions were observed in the third quarter of 2024 and, as such, nothing indicated the need for interim impairment testing. The Company also acquired In-Process Research & Development ("In-Process R & D") as part of the acquisitions of: Vaporsens; Air-Craftglass; Argil; and Guardian, each of which has been previously disclosed. The patents and intangible assets and related change in carrying values are set forth in the tables below: As of September 30, 2024: Other Intangible Assets Gross Accumulated Amortization Net Assumed Useful Life Gentex Patents $ 39,198,259 $ (27,882,575) $ 11,315,684 Various Other Intangible Assets HomeLink ® Trade Names and Trademarks $ 52,000,000 $ — $ 52,000,000 Indefinite HomeLink ® Technology 180,000,000 (165,000,000) 15,000,000 12 years Existing Customer Platforms 43,000,000 (43,000,000) — 10 years Exclusive Licensing Agreement 96,000,000 — 96,000,000 Indefinite eSight Technology 12,000,000 (916,667) 11,083,333 12 years eSight Trade Names and Trademarks 870,000 (66,458) 803,542 12 years Vaporsens In-Process R&D 11,000,000 — 11,000,000 Indefinite Argil In-Process R&D 6,278,132 — 6,278,132 Indefinite Air-Craftglass In-Process R&D 1,507,778 — 1,507,778 Indefinite Guardian Trade Names 1,300,000 (27,083) 1,272,917 12 years Guardian Technology 6,800,000 (141,667) 6,658,333 12 years Total Other Intangible Assets $ 410,755,910 $ (209,151,875) $ 201,604,035 Total Patents & Other Intangible Assets $ 449,954,169 $ (237,034,450) $ 212,919,719 As of December 31, 2023: Other Intangible Assets Gross Accumulated Amortization Net Assumed Useful Life Gentex Patents $ 39,199,107 $ (27,769,803) $ 11,429,304 Various Other Intangible Assets HomeLink ® Trade Names and Trademarks $ 52,000,000 $ — $ 52,000,000 Indefinite HomeLink ® Technology 180,000,000 (153,750,000) 26,250,000 12 years Existing Customer Platforms 43,000,000 (43,000,000) — 10 years Exclusive Licensing Agreement 96,000,000 — 96,000,000 Indefinite eSight Technology 12,000,000 — 12,000,000 12 years eSight Trade Names and Trademarks 870,000 — 870,000 12 years Vaporsens In-Process R&D 11,000,000 — 11,000,000 Indefinite Argil In-Process R&D 6,278,132 — 6,278,132 Indefinite Air-Craftglass In-Process R&D 1,507,778 — 1,507,778 Indefinite Guardian Trade Names 1,300,000 — 1,300,000 Indefinite Guardian In-Process R&D 6,800,000 — 6,800,000 Indefinite Total Other Intangible Assets $ 410,755,910 $ (196,750,000) $ 214,005,910 Total Patents & Other Intangible Assets $ 449,955,017 $ (224,519,803) $ 225,435,214 Amortization expense on patents and intangible assets was approximately $4.5 million and $13.4 million during the three and nine months ended September 30, 2024, respectively, compared to approximately $5.2 million and $15.6 million for the same periods ended September 30, 2023, respectively. Excluding the impact of any future acquisitions, the Company estimates amortization expense for the year ending December 31, 2024 to be approximately $18 million, for the year ending December 31, 2025 to be approximately $14 million, and for each of the years ending December 31, 2026, December 31, 2027, and December 31, 2028 to be approximately $3 million.

Investments

Investments	9 Months Ended
	Sep. 30, 2024
Investments [Abstract]
Investments	Investments Available for sale securities The Company follows the provisions of Accounting Standards Codification ("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 with respect to a company’s use of fair-value measurements, including the effect of such measurements on earnings. The cost of securities sold is based on the specific identification method. The Company determines the fair value of its government securities, asset-backed securities, municipal bonds, and corporate bonds by utilizing monthly valuation statements that are provided by its broker. The broker determines the investment valuation by utilizing the bid price in the market and also refers to third party sources to validate valuations, and as such are classified as Level 2 assets. The Company's certificates of deposit are classified as available for sale and are considered as Level 1 assets. These investments are carried at cost, which approximates fair value. On October 4, 2023, the Company entered into a Stock Purchase Agreement to acquire up to 3,137,500 shares of VOXX International Corporation ("VOXX") Class A Common Stock for investment purposes. The Company agreed to purchase the shares in two tranches: (1) on October 6, 2023, the Company purchased 1,568,750 shares of Class A Common Stock at a price of $10 per share, and (2) on January 5, 2024, the Company purchased 1,568,750 shares of Class A Common Stock at a price of $10 per share. On August 23, 2024, the Company entered into another Stock Purchase Agreement and acquired an additional 3,152,500 shares of Class A Common Stock on that date at $5 per share for investment purposes. The VOXX shares held by the Company are publicly traded and have a readily determinable fair market value and are considered Level 1 assets. The Company has the intention and current ability to hold the VOXX investment, and therefore has recorded the investment within Long-term Investments in the consolidated balance sheet. As of September 30, 2024, the Company holds a total of 6,463,808 shares of VOXX. As a result of the August 2024 purchase, the Company began accounting for the VOXX investment in accordance with ASC 323 – Investments – Equity Method and Joint Venture , with the election to use the Fair Value Option under ASC 825 - Fair Value . As a result of this election, changes in fair value of the shares are recorded in Investment income, net in the condensed consolidated statements of income. The Company recorded $14.9 million of gain during the three months ended September 30, 2024, and $9.0 million of loss during the nine months ended September 30, 2024 relating to mark to market adjustments in investment income related to VOXX. Technology Investments The Company also periodically makes strategic investments in the non-marketable debt or equity securities of other non-consolidated third parties ("Technology Investments"). Such Technology Investments totaled approximately $149.9 million as of September 30, 2024, of which $144.9 million and $5.0 million are recorded in long-term investments and short-term investments, respectively, on the consolidated balance sheet, and $128.0 million as of December 31, 2023, of which $124.6 million and $3.4 million are recorded in long-term investments and short-term investments, respectively, on the consolidated balance sheet. Depending on the form of investment, and the degree of influence the Company has over the investee, the Company primarily accounts for the Technology Investments in accordance with ASC 321, Investments- Equity Securities or ASC 323 – Investments – Equity Method and Joint Venture . The Company accounts for equity securities in non-controlled affiliates through which the Company exercises significant influence but do not have control over the investee under the equity method, with the Company’s share of the earnings or losses of non-controlled affiliates recognized within Other income (loss), net in the Company's condensed consolidated statement of income. All other Technology Investments that the Company holds are primarily accounted for under the measurement alternative of ASC 321. Under the measurement alternative, the carrying value is measured at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. Assets or liabilities that have recurring fair value measurements are shown below as of September 30, 2024 and December 31, 2023: As of September 30, 2024: Fair Value Measurements at Reporting Date Using Total as of Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description September 30, 2024 (Level 1) (Level 2) (Level 3) Cash & Cash Equivalents $ 179,639,743 $ 179,639,743 $ — $ — Short-Term Investments: Asset-backed Securities 2,784,681 — 2,784,681 — Certificate of Deposit 752,133 752,133 — — Corporate Bonds 3,960,920 — 3,960,920 — Government Securities 2,479,975 — 2,479,975 — Municipal Bonds 4,380,400 — 4,380,400 — Other 1,073,419 1,073,419 — — Long-Term Investments: Asset-backed Securities 40,069,030 — 40,069,030 — Corporate Bonds 57,754,563 — 57,754,563 — Government Securities 1,671,215 — 1,671,215 — Municipal Bonds 41,083,645 — 41,083,645 — Common Stock 41,109,820 41,109,820 — — Total $ 376,759,544 $ 222,575,115 $ 154,184,429 $ — As of December 31, 2023: Fair Value Measurements at Reporting Date Using Total as of Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description December 31, 2023 (Level 1) (Level 2) (Level 3) Cash & Cash Equivalents $ 226,435,019 $ 226,435,019 $ — $ — Short-Term Investments: Certificate of Deposit 994,013 994,013 — — Corporate Bonds 1,943,886 — 1,943,886 — Government Securities 4,759,507 — 4,759,507 — Municipal Bonds 1,726,658 — 1,726,658 — Other 1,465,388 1,465,388 — — Long-Term Investments: Asset-backed Securities 27,146,504 — 27,146,504 — Certificate of Deposit 748,358 748,358 — — Corporate Bonds 65,404,340 — 65,404,340 — Governmental Securities 6,227,129 — 6,227,129 — Municipal Bonds 56,336,921 — 56,336,921 Common Stock 18,610,519 18,610,519 — — Total $ 411,798,242 $ 248,253,297 $ 163,544,945 $ — The amortized cost, unrealized gains and losses, and market value of investment securities are shown as of September 30, 2024 and December 31, 2023: As of September 30, 2024: Unrealized Cost Gains Losses Market Value Short-Term Investments: Asset-backed Securities 2,834,713 — (50,032) 2,784,681 Certificate of Deposit $ 750,000 $ 2,133 $ — $ 752,133 Corporate Bonds 4,019,696 — (58,776) 3,960,920 Government Securities 2,474,160 5,815 — 2,479,975 Municipal Bonds 4,393,568 1,697 (14,865) 4,380,400 Other 1,073,419 — — 1,073,419 Long-Term Investments: Asset-backed Securities 39,109,728 1,032,389 (73,087) 40,069,030 Corporate Bonds 56,889,910 1,273,030 (408,377) 57,754,563 Government Securities 1,603,846 67,369 — 1,671,215 Municipal Bonds 41,175,200 918,479 (1,010,034) 41,083,645 Total $ 151,489,527 $ 3,300,912 $ (1,565,139) $ 153,225,300 As of December 31, 2023: Unrealized Cost Gains Losses Market Value Short-Term Investments: Certificate of Deposit $ 1,000,000 $ — $ (5,987) $ 994,013 Corporate Bonds 1,976,195 — (32,309) 1,943,886 Government Securities 4,754,495 21,141 (16,129) 4,759,507 Municipal Bonds 1,749,038 — (22,380) 1,726,658 Other 1,465,388 — — 1,465,388 Long-Term Investments: Asset-backed Securities 26,923,803 331,847 (109,146) 27,146,504 Certificate of Deposit 750,000 — (1,642) 748,358 Corporate Bonds 66,214,398 748,471 (1,558,529) 65,404,340 Government Securities 6,217,774 10,675 (1,320) 6,227,129 Municipal Bonds 58,261,615 811,128 (2,735,822) 56,336,921 Common Stock 17,324,886 1,328,446 (42,813) 18,610,519 Total $ 186,637,592 $ 3,251,708 $ (4,526,077) $ 185,363,223 Unrealized losses on available-for-sale securities as of September 30, 2024, are as follows: Aggregate Unrealized Losses Aggregate Fair Value of Investments Loss duration of less than one year $ 80,165 $ 7,363,296 Loss duration of greater than one year 1,535,006 46,320,380 Total $ 1,615,171 $ 53,683,676 Unrealized losses on available-for-sale securities as of December 31, 2023, are as follows: Aggregate Unrealized Losses Aggregate Fair Value of Investments Loss duration of less than one year $ 126,074 $ 13,449,592 Loss duration of greater than one year 4,400,003 76,966,258 Total $ 4,526,077 $ 90,415,850 Effective January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instrument s. The guidance modifies the impairment model for available-for-sale debt securities and provides a simplified accounting model for purchased financial assets with credit deterioration since their origination. The Company utilized the guidance provided by ASC 326 to determine whether any of the available-for-sale debt securities held by the Company were impaired. No investments were considered to be impaired during the periods presented. The Company has the intention and current ability to hold its debt investments until any amortized cost basis has been recovered. Due within one year $ 14,358,108 Due between one and five years 76,534,624 Due over five years 64,043,830 $ 154,936,562

Inventories, net

Inventories, net	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net Inventories consisted of the following at the respective balance sheet dates: September 30, 2024 December 31, 2023 Raw materials $ 317,505,698 $ 283,126,566 Work-in-process 47,856,981 46,343,955 Finished goods 83,948,341 73,002,507 Total Inventory $ 449,311,020 $ 402,473,028

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The Company has unvested share-based payment awards with a right to receive non-forfeitable dividends, which are considered participating securities under ASC 260, Earnings Per Share . The Company allocates earnings to participating securities and computes earnings per share using the two-class method. Under the two-class method, net income per share is computed by dividing net income allocated to common shareholders by the weighted average number of common shares outstanding for the period. In applying the two-class method, net income is allocated to both common shares and participating securities based on their respective weighted average shares outstanding for the period. For a period of net loss, net loss is not allocated to participating securities. The following table sets forth the computation of basic and diluted net income per common share under the two-class method for the three and nine months ended September 30, 2024 and September 30, 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Basic Earnings Per Share Net Income $ 122,549,041 $ 104,725,412 $ 316,820,194 $ 311,459,076 Less: Dividends and undistributed earnings allocated to participating securities 1,604,095 1,537,105 4,418,133 4,636,523 Net Income available to common shareholders $ 120,944,946 $ 103,188,307 $ 312,402,061 $ 306,822,553 Basic weighted average shares outstanding 226,002,347 230,047,014 226,646,541 229,866,008 Net Income per share - Basic $ 0.54 $ 0.45 $ 1.38 $ 1.33 Diluted Earnings Per Share Allocation of Net Income used in basic computation $ 120,944,946 $ 103,188,307 $ 312,402,061 $ 306,822,553 Reallocation of undistributed earnings 1,288 1,978 5,183 4,577 Net Income available to common shareholders - Diluted $ 120,946,234 $ 103,190,285 $ 312,407,244 $ 306,827,130 Number of shares used in basic computation 226,002,347 230,047,014 226,646,541 229,866,008 Additional weighted average dilutive common stock equivalents 239,337 410,397 363,391 315,666 Diluted weighted average shares outstanding 226,241,684 230,457,411 227,009,932 230,181,674 Net Income per share - Diluted $ 0.53 $ 0.45 $ 1.38 $ 1.33 Shares related to stock plans not included in diluted average common shares outstanding because their effect would be anti-dilutive 1,619,446 1,384,066 625,410 1,410,341

Stock-Based Compensation Plans

Stock-Based Compensation Plans	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans As of September 30, 2024, the Company had two equity incentive plans, which include the Gentex Corporation 2019 Omnibus Incentive Plan ("2019 Omnibus Plan"), and an employee stock purchase plan. Those plans and any prior material amendments thereto have previously been approved by shareholders. The 2019 Omnibus Plan provides for the potential awards to: i) employees; and ii) non-employee directors of the Company or its subsidiaries, which potential awards may be stock options (both incentive stock options and non-qualified stock options), appreciation rights, restricted stock awards and restricted stock units, performance share awards and performance units, and other awards that are stock-based, cash-based or a combination of both. The 2019 Omnibus Plan replaced the Company's Employee Stock Option Plan, Second Restricted Stock Plan, and Amended and Restated Non-Employee Director Stock Option Plan (the "Prior Plans"), which were also approved by shareholders. Any existing awards previously granted under the Prior Plans remain outstanding in accordance with their terms and are governed by the Prior Plans as applicable. Readers should refer to Note 5 of the consolidated financial statements in the Company's Annual Report on Form 10-K for the calendar year ended December 31, 2023, for additional information related to the Prior Plans. The Company recognized total compensation expense for share-based payments of $9,590,588 and $31,042,268 for the three and nine months ended September 30, 2024, respectively. The Company recognized compensation expense for share-based payments of $10,948,031 and $29,212,236 for the three and nine months ended September 30, 2023, respectively. A portion of the compensation cost for share based payment awards is capitalized as part of inventory. 2019 Omnibus Incentive Plan The purpose of the 2019 Omnibus Plan is to attract and retain employees, officers, and directors of the Company and its subsidiaries and to motivate and provide such persons incentives and rewards for performance. Pursuant to the terms of the 2019 Omnibus Plan, each type of award counts against the available shares based on a predetermined conversion rate (shown in the table below). As of September 30, 2024, 11,109,647 share awards have been made under the Plan, resulting in 29,672,008 shares granted of the 45,000,000 total shares available to be issued under the Plan. The shares issued are presented net of shares from canceled/expired options and shares. Shares Granted Conversion Rate Total Shares Under 2019 Omnibus Plan Non-Qualified Stock Options 5,043,516 1.00 5,043,516 Restricted Stock 5,049,480 4.06 20,500,889 Performance Shares 1,016,651 4.06 4,127,603 Total 11,109,647 29,672,008 Employee Stock Options Under the 2019 Omnibus Plan and the Employee Stock Option Plan, the option exercise price equals the stock’s market price on the date of grant. The options vest after one five The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the indicated periods: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Dividend Yield (1) 1.62 % 1.72 % 1.63 % 1.74 % Expected volatility (2) 27.92 % 28.66 % 28.07 % 28.89 % Risk-free interest rate (3) 3.58 % 4.60 % 4.04 % 4.11 % Expected term of options (years) (4) 4.14 4.14 4.14 4.15 Weighted-avg. grant date fair value $7.11 $8.40 $8.23 $7.54 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. Restricted shares awarded under the 2019 Omnibus Plan and the Second Restricted Stock 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 the Compensation Committee, appointed by the Board of Directors, but may not exceed ten years under the terms of such plans. As of September 30, 2024, the Company had unearned stock-based compensation of $52,836,541 associated with the restricted stock grants issued under the 2019 Omnibus Plan and the Second Restricted Stock Plan. The unearned stock-based compensation related to these grants is being amortized to compensation expense over the applicable restriction periods. Compensation expense from restricted stock grants in the three and nine months ended September 30, 2024 was $5,915,930 and $19,487,110, respectively. Compensation expense from restricted stock grants in the three and nine months ended September 30, 2023 was $6,369,348 and $18,178,157, respectively. Performance Shares Performance shares awarded under the 2019 Omnibus Plan are considered performance condition awards as attainment is based on the Company's performance relative to pre-established metrics. The fair value of such performance share awards was determined using the Company's average closing stock price on the twenty days preceding the date of grant. The expected attainment of the metrics for these awards is then analyzed each reporting period, and the related expense is adjusted based on expected attainment, if the then expected attainment differs from previous expectations. The cumulative effect on current and prior periods of a change in expected attainment is recognized in the period of change. As of September 30, 2024, the Company had unearned stock-based compensation of $15,768,739 associated with these performance share grants. The unearned stock-based compensation related to these grants is being amortized to compensation expense over the applicable performance periods. Compensation expense related to these performance share grants in the three and nine months ended September 30, 2024 was $1,573,201 and $5,369,466, respectively. Compensation expense related to these performance share grants in the three and nine months ended September 30, 2023 was $2,463,158 and $4,600,386, respectively. As part of its objective of attracting and retaining management to fulfill the Company's strategic goals, the Compensation Committee recommended and the Board approved on February 16, 2023, a retention grant of performance share awards ("PSAs"). In addition to the retention of management, the PSAs have been granted to further align management goals with those of the Company's shareholders. For that reason, the PSAs have been granted with performance criteria and will be based upon achievement of the Company's relative total shareholder return ("TSR") over a four year period (2023-2026), against a predetermined peer group. The grant date fair value of PSAs with TSR targets was determined using a Monte Carlo simulation. Compensation expense related to these retention grants in the three and nine months ended September 30, 2024 was $453,393 and $1,342,032, respectively. Compensation expense related to these retention grants in the three and nine months ended September 30, 2023 was $441,115 and $1,082,333, respectively. Employee Stock Purchase Plan Prior to July 1, 2022, the Company had in place an employee stock purchase plan covering 2,000,000 shares of common stock. Under that plan, the Company sold shares at 85% of the stock’s market price at date of purchase. Under ASC 718, Compensation - Stock Compensation , the 15% discounted value was recognized as compensation expense. As of September 30, 2024, the Company has issued 1,624,122 shares under this prior plan. In May 2022, the 2022 Gentex Corporation Employee Stock Purchase Plan covering 2,000,000 shares of common stock was approved by shareholders replacing the above referenced prior plan effective July 1, 2022. Under the 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. As of September 30, 2024, the Company has issued 442,718 shares under this plan.

Comprehensive Income (Loss)

Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) 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 debt investments and foreign currency translation adjustments. The following table presents the net changes in the Company's accumulated other comprehensive loss by component (all amounts shown are net of tax): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Foreign currency translation adjustments: Balance at beginning of period $ (5,994,473) $ (5,609,783) $ (4,534,719) $ (4,032,239) Other Comprehensive loss before reclassifications 1,776,813 (717,457) 317,059 (2,295,001) Net current-period change 1,776,813 (717,457) 317,059 (2,295,001) Balance at end of period (4,217,660) (6,327,240) (4,217,660) (6,327,240) Unrealized (losses) gains on available-for-sale debt securities: Balance at beginning of period (1,981,180) (7,632,985) (2,022,403) (10,110,695) Other Comprehensive (loss) income before reclassifications 3,294,853 (1,293,419) 2,465,099 (468,359) Amounts reclassified from accumulated other comprehensive income 18,063 1,580,904 889,040 3,233,554 Net current-period change 3,312,916 287,485 3,354,139 2,765,195 Balance at end of period 1,331,736 (7,345,500) 1,331,736 (7,345,500) Accumulated other comprehensive loss, end of period $ (2,885,924) $ (13,672,740) $ (2,885,924) $ (13,672,740) The following table presents details of reclassifications out of accumulated other comprehensive loss for the three and nine months ended September 30, 2024 and 2023: Details about Accumulated Other Comprehensive Loss Components Amounts Reclassified from Other Comprehensive Loss Affected Line item in the Consolidated Statements of Income Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Unrealized gains (losses) on available-for-sale debt securities Realized (loss) on sale of securities $ (22,864) $ (2,001,144) $ (1,125,367) $ (4,093,106) Other income (loss), net Provision for income taxes 4,801 420,240 236,327 859,552 Provision for income taxes Total net reclassifications for the period $ (18,063) $ (1,580,904) $ (889,040) $ (3,233,554)

Debt and Financing Arrangements

Debt and Financing Arrangements	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Debt and Financing Arrangements	Debt and Financing Arrangements On October 15, 2018, the Company entered into a credit agreement with PNC as the administrative agent and sole lender, which has now been amended and restated as discussed below. On February 21, 2023, as previously disclosed, the Company entered into an amended and restated credit agreement ("Credit Agreement") that provides for, among other things, a three-year unsecured revolving credit facility with a borrowing capacity of up to $250.0 million ("Revolver") that matures on February 21, 2026, replacing in its entirety the Company's above referenced prior $150.0 million revolving credit facility scheduled to mature on October 15, 2023. Included in the Revolver is a $20.0 million sublimit for standby letters of credit and a $35.0 million sublimit for swingline loans, each subject to certain conditions. Funds are available under the Revolver for working capital, capital expenditures, and other lawful corporate purposes, including, but not limited to, acquisitions and common stock repurchases, subject in each case to compliance with certain financial covenants, as defined in the Credit Agreement. As of September 30, 2024, there was no outstanding balance on the Revolver. As of September 30, 2024, the Company is in compliance with its covenants under the Credit Agreement.

Equity

Equity	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Equity	Equity The decrease in common stock during the nine months ended September 30, 2024, was primarily due to the repurchases of 5.8 million shares, partially offset by the issuance of 1.8 million shares of the Company’s common stock, net of cancellations, under the Company’s stock-based compensation plans. The total net decrease was 4.0 million shares. The Company recorded a cash dividend of $0.120 per share during the third quarter of 2024 as compared to a cash dividend of $0.120 per share during the third quarter of 2023. The third quarter 2024 dividend of $27.3 million was declared on August 30, 2024 and was paid on October 23, 2024.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Contingencies	ContingenciesThe Company is periodically involved in legal proceedings, legal actions and claims arising in the normal course of business, including proceedings relating to, for example, product liability, intellectual property, safety and health, employment, regulatory, 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 or cash flows of the Company.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company's automotive segment develops and manufactures digital vision and connected car products and electronics, including: automatic-dimming rearview mirrors with and without electronic features; non-auto dimming rearview mirrors with and without electronic features; and other electronics. The Company also develops and manufactures variably dimming windows and laminate products for the aerospace industry and fire protection products for the commercial construction industry. In 2020, the Company acquired Vaporsens, which specializes in nanofiber chemical sensing. In 2023, the Company acquired certain technology assets from eSight, which provides advanced and versatile low-vision smart glasses for those with visual impairments and is compatible with more than 20 eye conditions including Macular Degeneration, Diabetic Retinopathy, and Stargardt disease. These four non-automotive segments are combined into the "Other" segment as shown below. Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Revenue: Automotive Products $ 596,519,398 $ 564,510,277 $ 1,733,411,689 $ 1,676,043,013 Other 12,006,379 11,338,213 38,265,077 34,039,634 Total $ 608,525,777 $ 575,848,490 $ 1,771,676,766 $ 1,710,082,647 Income (Loss) from operations: Automotive Products $ 128,375,635 $ 121,875,176 $ 372,573,948 $ 362,044,032 Other (2,647,483) 541,353 (2,615,462) 912,532 Total $ 125,728,152 $ 122,416,529 $ 369,958,486 $ 362,956,564

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe effective tax rate was 15.4% in the nine months ended September 30, 2024, compared to an effective tax rate of 15.6% for the same period in 2023. Generally, effective tax rates for these periods differ from statutory federal income tax rates, due to provisions for state and local income taxes, permanent tax differences, the foreign-derived intangible income tax deduction, and research and development tax credits.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following table shows the Company’s Automotive revenue and Other Products revenue disaggregated by geographical location for Automotive Products for the three and nine month periods ended September 30, 2024 and September 30, 2023, respectively: Three Months Ended September 30, Nine Months Ended September 30, Revenue 2024 2023 2024 2023 Automotive Products U.S. $ 170,939,124 $ 171,312,177 $ 501,028,383 $ 520,034,256 Japan 100,415,089 73,330,091 271,681,510 229,664,642 Germany 69,610,212 72,169,634 216,815,930 226,739,945 Korea 41,644,963 44,257,034 126,797,525 101,655,653 Mexico 57,803,114 38,494,969 143,380,199 109,585,767 Other 156,106,896 164,946,372 473,708,142 488,362,750 Total Automotive Products $ 596,519,398 $ 564,510,277 $ 1,733,411,689 $ 1,676,043,013 Other Products (U.S.) 12,006,379 11,338,213 $ 38,265,077 $ 34,039,634 Total Revenue $ 608,525,777 $ 575,848,490 $ 1,771,676,766 $ 1,710,082,647 Revenue by geographic area may fluctuate based on many factors, including: exposure to local economic, political, and labor conditions; global supply chain constraints; unexpected changes in laws, regulations, trade or monetary or fiscal policy, including interest rates, foreign currency exchange rates and changes in the rate of inflation in the U.S. and other foreign countries; labor strikes, armed conflicts and acts of terrorism and war; and tariffs, quotas, customs and other import or export restrictions and other trade barriers. The following table disaggregates the Company’s Automotive revenue and Other revenue by major source for the three and nine month periods ended September 30, 2024 and September 30, 2023: Three Months Ended September 30, Nine Months Ended September 30, Revenue 2024 2023 2024 2023 Automotive Segment Automotive Mirrors & Electronics $ 559,477,924 $ 531,423,832 $ 1,640,221,054 $ 1,577,792,206 HomeLink Modules* 37,041,474 33,086,445 93,190,635 98,250,807 Total Automotive Products $ 596,519,398 $ 564,510,277 $ 1,733,411,689 $ 1,676,043,013 Other Segment Fire Protection Products 6,924,748 5,151,785 21,114,450 20,471,868 Aerospace Products 4,272,033 6,186,428 16,329,426 13,567,766 Medical Products 809,598 — $ 821,201 $ — Total Other $ 12,006,379 $ 11,338,213 $ 38,265,077 $ 34,039,634 *Excludes HomeLink revenue where HomeLink electronics are integrated into interior auto-dimming mirrors.

Leases

Leases	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Leases	Leases The Company has operating leases for certain sales, manufacturing, and engineering offices, as well as other vehicles and equipment, which are included within "Plant and Equipment - Net" section of the condensed consolidated balance sheets. The leases have remaining lease terms of 1 year to 5 years. The weighted average remaining lease term for operating leases as of September 30, 2024 was 4 years, with a weighted average discount rate of 6.0%. Future minimum lease payments for operating leases as of September 30, 2024 were as follows: Year ending December 31, 2024 (excluding the nine months ended September 30, 2024) $ 617,160 2025 1,913,864 2026 1,365,479 2027 1,018,929 2028 746,956 Thereafter 86,923 Total future minimum lease payments 5,749,311 Less imputed interest (385,941) Total $ 5,363,370 Reported as of September 30, 2024 Accrued Liabilities $ 2,079,966 Other Non-Current Liabilities 3,283,404 Total $ 5,363,370

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Acquisition	Acquisition On November 2, 2023, the Company, in the ordinary course of business, acquired certain technology assets from eSight for approximately $18.9 million in cash, the assumption of a $9.4 million promissory note given in exchange for the 20% equity the Company previously held in the assets, as well as an earn out provision over a ten year period. The earn out provision consists of multiple potential payments based on the revenue over the next ten The Company accounted for the acquisition under the provisions of FASB ASC Topic 805, Business Combinations . The valuation process was completed during the third quarter of 2024. Approximately $0.8 million of revenue of the business of eSight was included in the Company's consolidated statements of income and comprehensive income for the period ended September 30, 2024. The following table summarizes the fair values of the assets acquired, and the liabilities assumed, as of the acquisition date of November 2, 2023: Fair Value Current Assets $ 441,228 Personal Property 75,000 Right of Use Asset (Lease) 116,562 ESight Technology 12,000,000 Trade Names and Trademarks 870,000 Goodwill 26,696,012 Total Assets $ 40,198,802 Lease Liability $ 116,562 Contingent Earn Out Liability 12,000,000 Total Liabilities $ 12,116,562

Adoption of New Accounting St_2

Adoption of New Accounting Standards (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited condensed consolidated financial statements included herein have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. It is suggested that these unaudited condensed consolidated financial statements be read in conjunction with the financial statements and notes thereto included in the Company's 2023 annual report on Form 10-K. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments, consisting of only a normal and recurring nature, necessary to present fairly the financial position of the Company as of September 30, 2024, and the results of operations and cash flows for the interim periods presented.
Adoption of New Accounting Standards	Adoption of New Accounting Standards In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2023-07, Improvements to Reportable Segment Disclosures . This ASU updates reportable segment disclosure requirements by requiring disclosures of significant reportable segment expenses that are regularly provided to the Chief Operating Decision Maker (“CODM”) and included within each reported measure of a segment's profit or loss. This ASU also requires disclosure of the title and position of the individual identified as the CODM and an explanation of how the CODM uses the reported measures of a segment’s profit or loss in assessing segment performance and deciding how to allocate resources. The ASU is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Adoption of the ASU should be applied retrospectively to all prior periods presented in the financial statements. Early adoption is also permitted. The Company will likely include additional disclosures when this ASU is adopted by the Company. The Company is currently evaluating the provisions of this ASU and expects to adopt the ASU for the year ending December 31, 2024. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures . Under this ASU, public benefit entities must annually “(1) disclose specific categories in the rate reconciliation and (2) provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5 percent of the amount computed by multiplying pretax income (or loss) by the applicable statutory income tax rate).” This ASU is effective on a prospective basis for the Company in the fiscal year ending December 31, 2025. This ASU will result in additional disclosures being included in the consolidated financial statements once adopted.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The carrying value of Goodwill as of both September 30, 2024 and December 31, 2023 was $340.1 million , as set forth in the table below: Carrying Amount Balance as of December 31, 2023 $ 340,105,631 Acquisitions — Divestitures — Impairments — Other — Balance as of September 30, 2024 $ 340,105,631
Schedule of Intangible Assets	The patents and intangible assets and related change in carrying values are set forth in the tables below: As of September 30, 2024: Other Intangible Assets Gross Accumulated Amortization Net Assumed Useful Life Gentex Patents $ 39,198,259 $ (27,882,575) $ 11,315,684 Various Other Intangible Assets HomeLink ® Trade Names and Trademarks $ 52,000,000 $ — $ 52,000,000 Indefinite HomeLink ® Technology 180,000,000 (165,000,000) 15,000,000 12 years Existing Customer Platforms 43,000,000 (43,000,000) — 10 years Exclusive Licensing Agreement 96,000,000 — 96,000,000 Indefinite eSight Technology 12,000,000 (916,667) 11,083,333 12 years eSight Trade Names and Trademarks 870,000 (66,458) 803,542 12 years Vaporsens In-Process R&D 11,000,000 — 11,000,000 Indefinite Argil In-Process R&D 6,278,132 — 6,278,132 Indefinite Air-Craftglass In-Process R&D 1,507,778 — 1,507,778 Indefinite Guardian Trade Names 1,300,000 (27,083) 1,272,917 12 years Guardian Technology 6,800,000 (141,667) 6,658,333 12 years Total Other Intangible Assets $ 410,755,910 $ (209,151,875) $ 201,604,035 Total Patents & Other Intangible Assets $ 449,954,169 $ (237,034,450) $ 212,919,719 As of December 31, 2023: Other Intangible Assets Gross Accumulated Amortization Net Assumed Useful Life Gentex Patents $ 39,199,107 $ (27,769,803) $ 11,429,304 Various Other Intangible Assets HomeLink ® Trade Names and Trademarks $ 52,000,000 $ — $ 52,000,000 Indefinite HomeLink ® Technology 180,000,000 (153,750,000) 26,250,000 12 years Existing Customer Platforms 43,000,000 (43,000,000) — 10 years Exclusive Licensing Agreement 96,000,000 — 96,000,000 Indefinite eSight Technology 12,000,000 — 12,000,000 12 years eSight Trade Names and Trademarks 870,000 — 870,000 12 years Vaporsens In-Process R&D 11,000,000 — 11,000,000 Indefinite Argil In-Process R&D 6,278,132 — 6,278,132 Indefinite Air-Craftglass In-Process R&D 1,507,778 — 1,507,778 Indefinite Guardian Trade Names 1,300,000 — 1,300,000 Indefinite Guardian In-Process R&D 6,800,000 — 6,800,000 Indefinite Total Other Intangible Assets $ 410,755,910 $ (196,750,000) $ 214,005,910 Total Patents & Other Intangible Assets $ 449,955,017 $ (224,519,803) $ 225,435,214

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2024
Investments [Abstract]
Schedule of Investment Securities Stated at Fair Value	Assets or liabilities that have recurring fair value measurements are shown below as of September 30, 2024 and December 31, 2023: As of September 30, 2024: Fair Value Measurements at Reporting Date Using Total as of Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description September 30, 2024 (Level 1) (Level 2) (Level 3) Cash & Cash Equivalents $ 179,639,743 $ 179,639,743 $ — $ — Short-Term Investments: Asset-backed Securities 2,784,681 — 2,784,681 — Certificate of Deposit 752,133 752,133 — — Corporate Bonds 3,960,920 — 3,960,920 — Government Securities 2,479,975 — 2,479,975 — Municipal Bonds 4,380,400 — 4,380,400 — Other 1,073,419 1,073,419 — — Long-Term Investments: Asset-backed Securities 40,069,030 — 40,069,030 — Corporate Bonds 57,754,563 — 57,754,563 — Government Securities 1,671,215 — 1,671,215 — Municipal Bonds 41,083,645 — 41,083,645 — Common Stock 41,109,820 41,109,820 — — Total $ 376,759,544 $ 222,575,115 $ 154,184,429 $ — As of December 31, 2023: Fair Value Measurements at Reporting Date Using Total as of Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description December 31, 2023 (Level 1) (Level 2) (Level 3) Cash & Cash Equivalents $ 226,435,019 $ 226,435,019 $ — $ — Short-Term Investments: Certificate of Deposit 994,013 994,013 — — Corporate Bonds 1,943,886 — 1,943,886 — Government Securities 4,759,507 — 4,759,507 — Municipal Bonds 1,726,658 — 1,726,658 — Other 1,465,388 1,465,388 — — Long-Term Investments: Asset-backed Securities 27,146,504 — 27,146,504 — Certificate of Deposit 748,358 748,358 — — Corporate Bonds 65,404,340 — 65,404,340 — Governmental Securities 6,227,129 — 6,227,129 — Municipal Bonds 56,336,921 — 56,336,921 Common Stock 18,610,519 18,610,519 — — Total $ 411,798,242 $ 248,253,297 $ 163,544,945 $ —
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 September 30, 2024 and December 31, 2023: As of September 30, 2024: Unrealized Cost Gains Losses Market Value Short-Term Investments: Asset-backed Securities 2,834,713 — (50,032) 2,784,681 Certificate of Deposit $ 750,000 $ 2,133 $ — $ 752,133 Corporate Bonds 4,019,696 — (58,776) 3,960,920 Government Securities 2,474,160 5,815 — 2,479,975 Municipal Bonds 4,393,568 1,697 (14,865) 4,380,400 Other 1,073,419 — — 1,073,419 Long-Term Investments: Asset-backed Securities 39,109,728 1,032,389 (73,087) 40,069,030 Corporate Bonds 56,889,910 1,273,030 (408,377) 57,754,563 Government Securities 1,603,846 67,369 — 1,671,215 Municipal Bonds 41,175,200 918,479 (1,010,034) 41,083,645 Total $ 151,489,527 $ 3,300,912 $ (1,565,139) $ 153,225,300 As of December 31, 2023: Unrealized Cost Gains Losses Market Value Short-Term Investments: Certificate of Deposit $ 1,000,000 $ — $ (5,987) $ 994,013 Corporate Bonds 1,976,195 — (32,309) 1,943,886 Government Securities 4,754,495 21,141 (16,129) 4,759,507 Municipal Bonds 1,749,038 — (22,380) 1,726,658 Other 1,465,388 — — 1,465,388 Long-Term Investments: Asset-backed Securities 26,923,803 331,847 (109,146) 27,146,504 Certificate of Deposit 750,000 — (1,642) 748,358 Corporate Bonds 66,214,398 748,471 (1,558,529) 65,404,340 Government Securities 6,217,774 10,675 (1,320) 6,227,129 Municipal Bonds 58,261,615 811,128 (2,735,822) 56,336,921 Common Stock 17,324,886 1,328,446 (42,813) 18,610,519 Total $ 186,637,592 $ 3,251,708 $ (4,526,077) $ 185,363,223
Schedule of Unrealized Loss on available-for-sale securities	Unrealized losses on available-for-sale securities as of September 30, 2024, are as follows: Aggregate Unrealized Losses Aggregate Fair Value of Investments Loss duration of less than one year $ 80,165 $ 7,363,296 Loss duration of greater than one year 1,535,006 46,320,380 Total $ 1,615,171 $ 53,683,676 Unrealized losses on available-for-sale securities as of December 31, 2023, are as follows: Aggregate Unrealized Losses Aggregate Fair Value of Investments Loss duration of less than one year $ 126,074 $ 13,449,592 Loss duration of greater than one year 4,400,003 76,966,258 Total $ 4,526,077 $ 90,415,850
Schedule of Investments Classified by Contractual Maturity Date	Due within one year $ 14,358,108 Due between one and five years 76,534,624 Due over five years 64,043,830 $ 154,936,562

Inventories, net (Tables)

Inventories, net (Tables)	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following at the respective balance sheet dates: September 30, 2024 December 31, 2023 Raw materials $ 317,505,698 $ 283,126,566 Work-in-process 47,856,981 46,343,955 Finished goods 83,948,341 73,002,507 Total Inventory $ 449,311,020 $ 402,473,028

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of Earnings Per Share Basic and Diluted	The following table sets forth the computation of basic and diluted net income per common share under the two-class method for the three and nine months ended September 30, 2024 and September 30, 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Basic Earnings Per Share Net Income $ 122,549,041 $ 104,725,412 $ 316,820,194 $ 311,459,076 Less: Dividends and undistributed earnings allocated to participating securities 1,604,095 1,537,105 4,418,133 4,636,523 Net Income available to common shareholders $ 120,944,946 $ 103,188,307 $ 312,402,061 $ 306,822,553 Basic weighted average shares outstanding 226,002,347 230,047,014 226,646,541 229,866,008 Net Income per share - Basic $ 0.54 $ 0.45 $ 1.38 $ 1.33 Diluted Earnings Per Share Allocation of Net Income used in basic computation $ 120,944,946 $ 103,188,307 $ 312,402,061 $ 306,822,553 Reallocation of undistributed earnings 1,288 1,978 5,183 4,577 Net Income available to common shareholders - Diluted $ 120,946,234 $ 103,190,285 $ 312,407,244 $ 306,827,130 Number of shares used in basic computation 226,002,347 230,047,014 226,646,541 229,866,008 Additional weighted average dilutive common stock equivalents 239,337 410,397 363,391 315,666 Diluted weighted average shares outstanding 226,241,684 230,457,411 227,009,932 230,181,674 Net Income per share - Diluted $ 0.53 $ 0.45 $ 1.38 $ 1.33 Shares related to stock plans not included in diluted average common shares outstanding because their effect would be anti-dilutive 1,619,446 1,384,066 625,410 1,410,341

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Shares Issued, Net of Shares from Canceled/Expired Options and Shares	The shares issued are presented net of shares from canceled/expired options and shares. Shares Granted Conversion Rate Total Shares Under 2019 Omnibus Plan Non-Qualified Stock Options 5,043,516 1.00 5,043,516 Restricted Stock 5,049,480 4.06 20,500,889 Performance Shares 1,016,651 4.06 4,127,603 Total 11,109,647 29,672,008
Schedule of Weighted-Average Assumptions For The Employee Stock Option Plan	The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the indicated periods: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Dividend Yield (1) 1.62 % 1.72 % 1.63 % 1.74 % Expected volatility (2) 27.92 % 28.66 % 28.07 % 28.89 % Risk-free interest rate (3) 3.58 % 4.60 % 4.04 % 4.11 % Expected term of options (years) (4) 4.14 4.14 4.14 4.15 Weighted-avg. grant date fair value $7.11 $8.40 $8.23 $7.54 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.

Comprehensive Income (Loss) (Ta

Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Schedule of AOCI	The following table presents the net changes in the Company's accumulated other comprehensive loss by component (all amounts shown are net of tax): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Foreign currency translation adjustments: Balance at beginning of period $ (5,994,473) $ (5,609,783) $ (4,534,719) $ (4,032,239) Other Comprehensive loss before reclassifications 1,776,813 (717,457) 317,059 (2,295,001) Net current-period change 1,776,813 (717,457) 317,059 (2,295,001) Balance at end of period (4,217,660) (6,327,240) (4,217,660) (6,327,240) Unrealized (losses) gains on available-for-sale debt securities: Balance at beginning of period (1,981,180) (7,632,985) (2,022,403) (10,110,695) Other Comprehensive (loss) income before reclassifications 3,294,853 (1,293,419) 2,465,099 (468,359) Amounts reclassified from accumulated other comprehensive income 18,063 1,580,904 889,040 3,233,554 Net current-period change 3,312,916 287,485 3,354,139 2,765,195 Balance at end of period 1,331,736 (7,345,500) 1,331,736 (7,345,500) Accumulated other comprehensive loss, end of period $ (2,885,924) $ (13,672,740) $ (2,885,924) $ (13,672,740)
Schedule of Reclassifications Out of Other Comprehensive Income	The following table presents details of reclassifications out of accumulated other comprehensive loss for the three and nine months ended September 30, 2024 and 2023: Details about Accumulated Other Comprehensive Loss Components Amounts Reclassified from Other Comprehensive Loss Affected Line item in the Consolidated Statements of Income Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Unrealized gains (losses) on available-for-sale debt securities Realized (loss) on sale of securities $ (22,864) $ (2,001,144) $ (1,125,367) $ (4,093,106) Other income (loss), net Provision for income taxes 4,801 420,240 236,327 859,552 Provision for income taxes Total net reclassifications for the period $ (18,063) $ (1,580,904) $ (889,040) $ (3,233,554)

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Schedule of Segments	These four non-automotive segments are combined into the "Other" segment as shown below. Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Revenue: Automotive Products $ 596,519,398 $ 564,510,277 $ 1,733,411,689 $ 1,676,043,013 Other 12,006,379 11,338,213 38,265,077 34,039,634 Total $ 608,525,777 $ 575,848,490 $ 1,771,676,766 $ 1,710,082,647 Income (Loss) from operations: Automotive Products $ 128,375,635 $ 121,875,176 $ 372,573,948 $ 362,044,032 Other (2,647,483) 541,353 (2,615,462) 912,532 Total $ 125,728,152 $ 122,416,529 $ 369,958,486 $ 362,956,564

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table shows the Company’s Automotive revenue and Other Products revenue disaggregated by geographical location for Automotive Products for the three and nine month periods ended September 30, 2024 and September 30, 2023, respectively: Three Months Ended September 30, Nine Months Ended September 30, Revenue 2024 2023 2024 2023 Automotive Products U.S. $ 170,939,124 $ 171,312,177 $ 501,028,383 $ 520,034,256 Japan 100,415,089 73,330,091 271,681,510 229,664,642 Germany 69,610,212 72,169,634 216,815,930 226,739,945 Korea 41,644,963 44,257,034 126,797,525 101,655,653 Mexico 57,803,114 38,494,969 143,380,199 109,585,767 Other 156,106,896 164,946,372 473,708,142 488,362,750 Total Automotive Products $ 596,519,398 $ 564,510,277 $ 1,733,411,689 $ 1,676,043,013 Other Products (U.S.) 12,006,379 11,338,213 $ 38,265,077 $ 34,039,634 Total Revenue $ 608,525,777 $ 575,848,490 $ 1,771,676,766 $ 1,710,082,647 The following table disaggregates the Company’s Automotive revenue and Other revenue by major source for the three and nine month periods ended September 30, 2024 and September 30, 2023: Three Months Ended September 30, Nine Months Ended September 30, Revenue 2024 2023 2024 2023 Automotive Segment Automotive Mirrors & Electronics $ 559,477,924 $ 531,423,832 $ 1,640,221,054 $ 1,577,792,206 HomeLink Modules* 37,041,474 33,086,445 93,190,635 98,250,807 Total Automotive Products $ 596,519,398 $ 564,510,277 $ 1,733,411,689 $ 1,676,043,013 Other Segment Fire Protection Products 6,924,748 5,151,785 21,114,450 20,471,868 Aerospace Products 4,272,033 6,186,428 16,329,426 13,567,766 Medical Products 809,598 — $ 821,201 $ — Total Other $ 12,006,379 $ 11,338,213 $ 38,265,077 $ 34,039,634 *Excludes HomeLink revenue where HomeLink electronics are integrated into interior auto-dimming mirrors.

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Schedule of Future Minimum Lease Payments	Future minimum lease payments for operating leases as of September 30, 2024 were as follows: Year ending December 31, 2024 (excluding the nine months ended September 30, 2024) $ 617,160 2025 1,913,864 2026 1,365,479 2027 1,018,929 2028 746,956 Thereafter 86,923 Total future minimum lease payments 5,749,311 Less imputed interest (385,941) Total $ 5,363,370
Schedule of Lease Liabilities	Reported as of September 30, 2024 Accrued Liabilities $ 2,079,966 Other Non-Current Liabilities 3,283,404 Total $ 5,363,370

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Schedule of Assets Acquired and Liabilities Assumed	The following table summarizes the fair values of the assets acquired, and the liabilities assumed, as of the acquisition date of November 2, 2023: Fair Value Current Assets $ 441,228 Personal Property 75,000 Right of Use Asset (Lease) 116,562 ESight Technology 12,000,000 Trade Names and Trademarks 870,000 Goodwill 26,696,012 Total Assets $ 40,198,802 Lease Liability $ 116,562 Contingent Earn Out Liability 12,000,000 Total Liabilities $ 12,116,562

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023		Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2021	Dec. 31, 2020	Nov. 02, 2023	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 340,105,631	$ 340,105,631	[1]		$ 340,105,631
Acquisitions					0
Amortization of intangible assets	4,500,000			$ 5,200,000	13,400,000	$ 15,600,000
Total Patents & Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Amortization expense, remainder of 2024	18,000,000				18,000,000
Amortization expense, year 2025	14,000,000				14,000,000
Amortization expense, year 2026	3,000,000				3,000,000
Amortization expense, year 2027	3,000,000				3,000,000
Amortization expense, year 2028	$ 3,000,000				$ 3,000,000
HomeLink®
Finite-Lived Intangible Assets [Line Items]
Goodwill										$ 307,400,000
Vaporsens
Finite-Lived Intangible Assets [Line Items]
Acquisitions								$ 3,700,000
Air-CraftGlass
Finite-Lived Intangible Assets [Line Items]
Acquisitions								200,000
Argil
Finite-Lived Intangible Assets [Line Items]
Acquisitions								$ 1,000,000
Guardian
Finite-Lived Intangible Assets [Line Items]
Acquisitions							$ 2,000,000
eSight
Finite-Lived Intangible Assets [Line Items]
Goodwill									$ 26,696,012
Acquisitions		$ 26,700,000
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of Goodwill (Details)	9 Months Ended
	Sep. 30, 2024 USD ($)
Carrying Amount
Balance at beginning of period	$ 340,105,631	[1]
Acquisitions	0
Divestitures	0
Impairments	0
Other	0
Balance at end of period	$ 340,105,631
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 201,604,035	$ 214,005,910	[1]
Trademarks and Trade Names | HomeLink®
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	52,000,000	52,000,000
Trademarks and Trade Names | Guardian
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets		1,300,000
Exclusive Licensing Agreement
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	96,000,000	96,000,000
In Process Research and Development | Vaporsens
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	11,000,000	11,000,000
In Process Research and Development | Argil
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	6,278,132	6,278,132
In Process Research and Development | Air-CraftGlass
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	1,507,778	1,507,778
In Process Research and Development | Guardian
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets		6,800,000
Gentex Patents
Finite-Lived Intangible Assets [Line Items]
Gross	39,198,259	39,199,107
Accumulated Amortization	(27,882,575)	(27,769,803)
Net	11,315,684	11,429,304
Total Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	(209,151,875)	(196,750,000)
Intangible assets, gross	410,755,910	410,755,910
Intangible assets, net	201,604,035	214,005,910
Technology | HomeLink®
Finite-Lived Intangible Assets [Line Items]
Gross	180,000,000	180,000,000
Accumulated Amortization	(165,000,000)	(153,750,000)
Net	$ 15,000,000	$ 26,250,000
Assumed Useful Life	12 years	12 years
Technology | eSight
Finite-Lived Intangible Assets [Line Items]
Gross	$ 12,000,000	$ 12,000,000
Accumulated Amortization	(916,667)
Net	$ 11,083,333	$ 12,000,000
Assumed Useful Life	12 years	12 years
Technology | Guardian
Finite-Lived Intangible Assets [Line Items]
Gross	$ 6,800,000
Accumulated Amortization	(141,667)
Net	$ 6,658,333
Assumed Useful Life	12 years
Existing Customer Platforms
Finite-Lived Intangible Assets [Line Items]
Gross	$ 43,000,000	$ 43,000,000
Accumulated Amortization	(43,000,000)	(43,000,000)
Net	$ 0	$ 0
Assumed Useful Life	10 years	10 years
Trademarks and Trade Names | eSight
Finite-Lived Intangible Assets [Line Items]
Gross	$ 870,000	$ 870,000
Accumulated Amortization	(66,458)
Net	$ 803,542	$ 870,000
Assumed Useful Life	12 years	12 years
Trademarks and Trade Names | Guardian
Finite-Lived Intangible Assets [Line Items]
Gross	$ 1,300,000
Accumulated Amortization	(27,083)
Net	$ 1,272,917
Assumed Useful Life	12 years
Total Patents & Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Total Patents & Other Intangible Assets, Gross	$ 449,954,169	$ 449,955,017
Total Patents & Other Intangible Assets, Accumulated Amortization	(237,034,450)	(224,519,803)
Total Patents & Other Intangible Assets, Net	$ 212,919,719	$ 225,435,214
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Investments - Narrative (Detail

Investments - Narrative (Details) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2024 USD ($) shares	Sep. 30, 2024 USD ($) shares	Aug. 23, 2024 $ / shares shares	Jan. 05, 2024 $ / shares shares	Dec. 31, 2023 USD ($)	Oct. 06, 2023 $ / shares shares	Oct. 04, 2023 tranche shares
Debt and Equity Securities, FV-NI [Line Items]
Technology investments	$ 149.9	$ 149.9			$ 128
Long-term Investments
Debt and Equity Securities, FV-NI [Line Items]
Technology investments	144.9	144.9			124.6
Short-Term Investments
Debt and Equity Securities, FV-NI [Line Items]
Technology investments	$ 5	$ 5			$ 3.4
VOXX International Corporation
Debt and Equity Securities, FV-NI [Line Items]
Shares of investment held (in shares) | shares	6,463,808	6,463,808
Gain (loss) relating to mark to market adjustment in investment income	$ 14.9	$ (9)
VOXX International Corporation
Debt and Equity Securities, FV-NI [Line Items]
Number of tranches | tranche							2
VOXX International Corporation | Common Class A
Debt and Equity Securities, FV-NI [Line Items]
Number of shares acquired (in shares) | shares			3,152,500	1,568,750		1,568,750	3,137,500
Shares purchased, price per share (in dollars per share) | $ / shares			$ 5	$ 10		$ 10

Investments - Schedule of Asset

Investments - Schedule of Assets or Liabilities, Recurring Fair Value Measurements (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	$ 179,639,743	$ 226,435,019
Total	376,759,544	411,798,242
Short-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,784,681
Short-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	752,133	994,013
Short-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	3,960,920	1,943,886
Short-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,479,975	4,759,507
Short-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	4,380,400	1,726,658
Short-Term Investments | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,073,419	1,465,388
Long-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	40,069,030	27,146,504
Long-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		748,358
Long-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	57,754,563	65,404,340
Long-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,671,215	6,227,129
Long-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	41,083,645	56,336,921
Long-Term Investments | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	41,109,820	18,610,519
(Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	179,639,743	226,435,019
Total	222,575,115	248,253,297
(Level 1) | Short-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0
(Level 1) | Short-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	752,133	994,013
(Level 1) | Short-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Short-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Short-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Short-Term Investments | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,073,419	1,465,388
(Level 1) | Long-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Long-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		748,358
(Level 1) | Long-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Long-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Long-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Long-Term Investments | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	41,109,820	18,610,519
(Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	0	0
Total	154,184,429	163,544,945
(Level 2) | Short-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,784,681
(Level 2) | Short-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 2) | Short-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	3,960,920	1,943,886
(Level 2) | Short-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,479,975	4,759,507
(Level 2) | Short-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	4,380,400	1,726,658
(Level 2) | Short-Term Investments | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 2) | Long-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	40,069,030	27,146,504
(Level 2) | Long-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		0
(Level 2) | Long-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	57,754,563	65,404,340
(Level 2) | Long-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,671,215	6,227,129
(Level 2) | Long-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	41,083,645	56,336,921
(Level 2) | Long-Term Investments | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash & Cash Equivalents	0	0
Total	0	0
(Level 3) | Short-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0
(Level 3) | Short-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Short-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Short-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Short-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Short-Term Investments | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Long-Term Investments | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Long-Term Investments | Certificate of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		0
(Level 3) | Long-Term Investments | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Long-Term Investments | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Long-Term Investments | Municipal Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0
(Level 3) | Long-Term Investments | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$ 0	$ 0

Investments - Schedule of Amort

Investments - Schedule of Amortized Cost, Unrealized Gains and Losses, and Market Value of Investment Securities (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Cost	$ 151,489,527	$ 186,637,592
Unrealized Gains	3,300,912	3,251,708
Unrealized Losses	(1,565,139)	(4,526,077)
Market Value	153,225,300	185,363,223
Short-Term Investments | Asset-backed Securities
Debt Securities, Available-for-sale [Line Items]
Cost	2,834,713
Unrealized Gains	0
Unrealized Losses	(50,032)
Market Value	2,784,681
Short-Term Investments | Certificate of Deposit
Debt Securities, Available-for-sale [Line Items]
Cost	750,000	1,000,000
Unrealized Gains	2,133	0
Unrealized Losses	0	(5,987)
Market Value	752,133	994,013
Short-Term Investments | Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Cost	4,019,696	1,976,195
Unrealized Gains	0	0
Unrealized Losses	(58,776)	(32,309)
Market Value	3,960,920	1,943,886
Short-Term Investments | Government Securities
Debt Securities, Available-for-sale [Line Items]
Cost	2,474,160	4,754,495
Unrealized Gains	5,815	21,141
Unrealized Losses	0	(16,129)
Market Value	2,479,975	4,759,507
Short-Term Investments | Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Cost	4,393,568	1,749,038
Unrealized Gains	1,697	0
Unrealized Losses	(14,865)	(22,380)
Market Value	4,380,400	1,726,658
Short-Term Investments | Other
Debt Securities, Available-for-sale [Line Items]
Cost	1,073,419	1,465,388
Unrealized Gains	0	0
Unrealized Losses	0	0
Market Value	1,073,419	1,465,388
Long-Term Investments | Asset-backed Securities
Debt Securities, Available-for-sale [Line Items]
Cost	39,109,728	26,923,803
Unrealized Gains	1,032,389	331,847
Unrealized Losses	(73,087)	(109,146)
Market Value	40,069,030	27,146,504
Long-Term Investments | Certificate of Deposit
Debt Securities, Available-for-sale [Line Items]
Cost		750,000
Unrealized Gains		0
Unrealized Losses		(1,642)
Market Value		748,358
Long-Term Investments | Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Cost	56,889,910	66,214,398
Unrealized Gains	1,273,030	748,471
Unrealized Losses	(408,377)	(1,558,529)
Market Value	57,754,563	65,404,340
Long-Term Investments | Government Securities
Debt Securities, Available-for-sale [Line Items]
Cost	1,603,846	6,217,774
Unrealized Gains	67,369	10,675
Unrealized Losses	0	(1,320)
Market Value	1,671,215	6,227,129
Long-Term Investments | Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Cost	41,175,200	58,261,615
Unrealized Gains	918,479	811,128
Unrealized Losses	(1,010,034)	(2,735,822)
Market Value	$ 41,083,645	56,336,921
Long-Term Investments | Common Stock
Debt Securities, Available-for-sale [Line Items]
Cost		17,324,886
Unrealized Gains		1,328,446
Unrealized Losses		(42,813)
Market Value		$ 18,610,519

Investments - Schedule of Unrea

Investments - Schedule of Unrealized Loss on available-for-sale securities (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Aggregate Unrealized Losses
Loss duration of less than one year	$ 80,165	$ 126,074
Loss duration of greater than one year	1,535,006	4,400,003
Total	1,615,171	4,526,077
Aggregate Fair Value of Investments
Loss duration of less than one year	7,363,296	13,449,592
Loss duration of greater than one year	46,320,380	76,966,258
Total	$ 53,683,676	$ 90,415,850

Investments - Schedule of Inves

Investments - Schedule of Investments Classified by Contractual Maturity Date (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Total	$ 153,225,300	$ 185,363,223
Fixed Income Securities
Debt Securities, Available-for-sale [Line Items]
Due within one year	14,358,108
Due between one and five years	76,534,624
Due over five years	64,043,830
Total	$ 154,936,562

Inventories, net (Details)

Inventories, net (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 317,505,698	$ 283,126,566
Work-in-process	47,856,981	46,343,955
Finished goods	83,948,341	73,002,507
Total Inventory	$ 449,311,020	$ 402,473,028	[1]
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Basic Earnings Per Share
Net income		$ 122,549,041	$ 104,725,412	$ 316,820,194	$ 311,459,076
Less: Dividends and undistributed earnings allocated to participating securities		1,604,095	1,537,105	4,418,133	4,636,523
Net Income available to common shareholders		$ 120,944,946	$ 103,188,307	$ 312,402,061	$ 306,822,553
Basic weighted average shares outstanding (in shares)		226,002,347	230,047,014	226,646,541	229,866,008
Net income per share - Basic (in dollars per share)	[1]	$ 0.54	$ 0.45	$ 1.38	$ 1.33
Diluted Earnings Per Share
Allocation of Net Income used in basic computation		$ 120,944,946	$ 103,188,307	$ 312,402,061	$ 306,822,553
Reallocation of undistributed earnings		1,288	1,978	5,183	4,577
Net Income available to common shareholders - Diluted		$ 120,946,234	$ 103,190,285	$ 312,407,244	$ 306,827,130
Number of shares used in basic computation (in shares)		226,002,347	230,047,014	226,646,541	229,866,008
Additional weighted average dilutive common stock equivalents (in shares)		239,337	410,397	363,391	315,666
Diluted weighted average shares outstanding (in shares)		226,241,684	230,457,411	227,009,932	230,181,674
Net Income per share - Diluted (in dollars per share)	[1]	$ 0.53	$ 0.45	$ 1.38	$ 1.33
Shares related to stock plans not included in diluted average common shares outstanding because their effect would be anti-dilutive (in shares)		1,619,446	1,384,066	625,410	1,410,341
[1] (1) Earnings Per Share has been adjusted to exclude the portion of net income allocated to participating securities as a result of share-based payment awards.

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Narrative (Details)		1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2022 shares	May 31, 2022 shares	Sep. 30, 2024 USD ($) plan shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) plan shares	Sep. 30, 2023 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments | $			$ 9,590,588	$ 10,948,031	$ 31,042,268	$ 29,212,236
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the omnibus plan (in shares)					1,624,122
Number of shares authorized (in shares)	2,000,000
ESPP discount rate	85%
ESPP discount rate recognized as compensation expense	15%
Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grants in period (in shares)					11,109,647
Shares issued under the omnibus plan (in shares)					29,672,008
Number of shares authorized (in shares)			45,000,000		45,000,000
Employee Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost | $			$ 5,834,690		$ 5,834,690
Employee Stock Option Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period					1 year
Option expiration period					5 years
Employee Stock Option Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period					5 years
Option expiration period					10 years
Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost | $			52,836,541		$ 52,836,541
Restricted period, maximum					10 years
Amortization expense | $			$ 5,915,930	6,369,348	$ 19,487,110	18,178,157
Gentex Corporation Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the omnibus plan (in shares)					442,718
Number of shares authorized (in shares)		2,000,000
ESPP discount rate		85%
ESPP discount rate recognized as compensation expense		15%
Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans | plan			2		2
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments | $			$ 1,573,201	2,463,158	$ 5,369,466	4,600,386
Unrecognized compensation cost | $			15,768,739		$ 15,768,739
Performance Shares | Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the omnibus plan (in shares)					4,127,603
Performance Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments | $			$ 453,393	$ 441,115	$ 1,342,032	$ 1,082,333
Option vesting period					4 years

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Schedule of Shares Issued Net of Shares Canceled/Expired (Details) - Omnibus Incentive Plan	9 Months Ended
	Sep. 30, 2024 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grants in period (in shares)	11,109,647
Shares issued under the omnibus plan (in shares)	29,672,008
Non-Qualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted, options (in shares)	5,043,516
Conversion rate, options	1
Shares issued under the omnibus plan (in shares)	5,043,516
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	5,049,480
Conversion rate, shares	4.06
Shares issued under the omnibus plan (in shares)	20,500,889
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	1,016,651
Conversion rate, shares	4.06
Shares issued under the omnibus plan (in shares)	4,127,603

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - Schedule of Weighted-Average Assumptions for the ESOP (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Dividend yield	1.62%	1.72%	1.63%	1.74%
Expected volatility	27.92%	28.66%	28.07%	28.89%
Risk-free interest rate	3.58%	4.60%	4.04%	4.11%
Expected term of options (years)	4 years 1 month 20 days	4 years 1 month 20 days	4 years 1 month 20 days	4 years 1 month 24 days
Weighted-avg. grant date fair value (in dollars per share)	$ 7.11	$ 8.40	$ 8.23	$ 7.54

Comprehensive Income (Loss) - S

Comprehensive Income (Loss) - Schedule of AOCI (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024		Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 2,400,299,527	$ 2,195,949,326	$ 2,312,517,069	[1]	$ 2,065,792,821
Other comprehensive (loss) income, net of tax	5,089,729	(429,972)	3,671,198		470,194
Balance at end of period	2,417,627,342	2,268,453,807	2,417,627,342		2,268,453,807
Accumulated Other Comprehensive Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(7,975,653)	(13,242,768)	(6,557,122)		(14,142,934)
Balance at end of period	(2,885,924)	(13,672,740)	(2,885,924)		(13,672,740)
Foreign currency translation adjustments:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(5,994,473)	(5,609,783)	(4,534,719)		(4,032,239)
Other Comprehensive (loss) income before reclassifications	1,776,813	(717,457)	317,059		(2,295,001)
Other comprehensive (loss) income, net of tax	1,776,813	(717,457)	317,059		(2,295,001)
Balance at end of period	(4,217,660)	(6,327,240)	(4,217,660)		(6,327,240)
Unrealized gains (losses) on available-for-sale debt securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(1,981,180)	(7,632,985)	(2,022,403)		(10,110,695)
Other Comprehensive (loss) income before reclassifications	3,294,853	(1,293,419)	2,465,099		(468,359)
Amounts reclassified from accumulated other comprehensive income	18,063	1,580,904	889,040		3,233,554
Other comprehensive (loss) income, net of tax	3,312,916	287,485	3,354,139		2,765,195
Balance at end of period	$ 1,331,736	$ (7,345,500)	$ 1,331,736		$ (7,345,500)
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Comprehensive Income (Loss) -_2

Comprehensive Income (Loss) - Schedule of Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized (loss) on sale of securities	$ 744,569	$ (1,788,335)	$ 1,255,438	$ (3,559,613)
Provision for income taxes	(22,906,309)	(19,754,749)	(57,614,063)	(57,619,971)
Total net reclassifications for the period	122,549,041	104,725,412	316,820,194	311,459,076
Amounts Reclassified from Other Comprehensive Loss | Unrealized gains (losses) on available-for-sale debt securities
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Realized (loss) on sale of securities	(22,864)	(2,001,144)	(1,125,367)	(4,093,106)
Provision for income taxes	4,801	420,240	236,327	859,552
Total net reclassifications for the period	$ (18,063)	$ (1,580,904)	$ (889,040)	$ (3,233,554)

Debt and Financing Arrangemen_2

Debt and Financing Arrangements (Details) - USD ($)	Feb. 21, 2023	Sep. 30, 2024
Revolving Facility
Debt Instrument [Line Items]
Debt instrument, term	3 years
Principal amount	$ 250,000,000
Additional borrowings available	150,000,000
Long-term debt		$ 0
Letter of Credit
Debt Instrument [Line Items]
Additional borrowings available	20,000,000
Swing Loans
Debt Instrument [Line Items]
Additional borrowings available	$ 35,000,000

Equity (Details)

Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Equity [Abstract]
Stock repurchased (in shares)			5.8
Common stock issued under stock compensation plan (in shares)			1.8
Net increase (decrease) in common stock (in shares)			(4)
Dividends declared (in dollars per share)	$ 0.12	$ 0.12	$ 0.36	$ 0.36
Value of dividends declared	$ 27.3

Segment Reporting (Details)

Segment Reporting (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($)
Segment Reporting Information [Line Items]
Revenue:	$ 608,525,777	$ 575,848,490	$ 1,771,676,766	$ 1,710,082,647
Income (Loss) from operations:	125,728,152	122,416,529	$ 369,958,486	362,956,564
Other
Segment Reporting Information [Line Items]
Number of non-automotive segments | segment			4
Revenue:	12,006,379	11,338,213	$ 38,265,077	34,039,634
Income (Loss) from operations:	(2,647,483)	541,353	(2,615,462)	912,532
Automotive Products
Segment Reporting Information [Line Items]
Revenue:	596,519,398	564,510,277	1,733,411,689	1,676,043,013
Income (Loss) from operations:	$ 128,375,635	$ 121,875,176	$ 372,573,948	$ 362,044,032

Income Taxes (Details)

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Effective income tax rate	15.40%	15.60%

Revenue (Details)

Revenue (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total Revenue	$ 608,525,777	$ 575,848,490	$ 1,771,676,766	$ 1,710,082,647
Automotive Products
Disaggregation of Revenue [Line Items]
Total Revenue	596,519,398	564,510,277	1,733,411,689	1,676,043,013
Automotive Products | Automotive Segment
Disaggregation of Revenue [Line Items]
Total Revenue	596,519,398	564,510,277	1,733,411,689	1,676,043,013
Automotive Products | U.S.
Disaggregation of Revenue [Line Items]
Total Revenue	170,939,124	171,312,177	501,028,383	520,034,256
Automotive Products | Japan
Disaggregation of Revenue [Line Items]
Total Revenue	100,415,089	73,330,091	271,681,510	229,664,642
Automotive Products | Germany
Disaggregation of Revenue [Line Items]
Total Revenue	69,610,212	72,169,634	216,815,930	226,739,945
Automotive Products | Korea
Disaggregation of Revenue [Line Items]
Total Revenue	41,644,963	44,257,034	126,797,525	101,655,653
Automotive Products | Mexico
Disaggregation of Revenue [Line Items]
Total Revenue	57,803,114	38,494,969	143,380,199	109,585,767
Automotive Products | Other
Disaggregation of Revenue [Line Items]
Total Revenue	156,106,896	164,946,372	473,708,142	488,362,750
Automotive Mirrors & Electronics | Automotive Segment
Disaggregation of Revenue [Line Items]
Total Revenue	559,477,924	531,423,832	1,640,221,054	1,577,792,206
HomeLink Modules | Automotive Segment
Disaggregation of Revenue [Line Items]
Total Revenue	37,041,474	33,086,445	93,190,635	98,250,807
Other Products | Other Segment
Disaggregation of Revenue [Line Items]
Total Revenue	12,006,379	11,338,213	38,265,077	34,039,634
Other Products | U.S.
Disaggregation of Revenue [Line Items]
Total Revenue	12,006,379	11,338,213	38,265,077	34,039,634
Fire Protection Products | Other Segment
Disaggregation of Revenue [Line Items]
Total Revenue	6,924,748	5,151,785	21,114,450	20,471,868
Aerospace Products | Other Segment
Disaggregation of Revenue [Line Items]
Total Revenue	4,272,033	6,186,428	16,329,426	13,567,766
Medical Products | Other Segment
Disaggregation of Revenue [Line Items]
Total Revenue	$ 809,598	$ 0	$ 821,201	$ 0

Leases - Narrative (Details)

Leases - Narrative (Details)	Sep. 30, 2024
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term	4 years
Weighted average discount rate	6%
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	5 years

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Lease Payments and Liabilities (Details)	Sep. 30, 2024 USD ($)
Leases [Abstract]
2024 (excluding the nine months ended September 30, 2024)	$ 617,160
2025	1,913,864
2026	1,365,479
2027	1,018,929
2028	746,956
Thereafter	86,923
Total future minimum lease payments	5,749,311
Less imputed interest	(385,941)
Total	5,363,370
Accrued Liabilities	$ 2,079,966
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued liabilities
Other Non-Current Liabilities	$ 3,283,404
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	OTHER NON-CURRENT LIABILITIES

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - eSight Corporation - USD ($) $ in Millions		9 Months Ended
	Nov. 02, 2023	Sep. 30, 2024
Business Acquisition [Line Items]
Cash paid to acquire business	$ 18.9
Assumption of promissory note	$ 9.4
Equity interest percentage in acquiree previously held	20%
Earn out provision period	10 years
Total earn out, maximum potential payment	$ 70
Revenue from business included in statement of income and comprehensive income		$ 0.8

Acquisition - Schedule of Asset

Acquisition - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023	[1]	Nov. 02, 2023
Fair Value
Goodwill	$ 340,105,631	$ 340,105,631
eSight Corporation
Fair Value
Current Assets				$ 441,228
Personal Property				75,000
Right of Use Asset (Lease)				116,562
Goodwill				26,696,012
Total Assets				40,198,802
Lease Liability				116,562
Contingent Earn Out Liability				12,000,000
Total Liabilities				12,116,562
eSight Corporation | ESight Technology
Fair Value
Intangible assets				12,000,000
eSight Corporation | Trade Names and Trademarks
Fair Value
Intangible assets				$ 870,000
[1]The condensed consolidated balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.