Consolidated Statements of Stockholders' Equity - USD ($)	Total	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Class A Common Stock [Member]	Class B Common Stock [Member]
Beginning balance at Dec. 31, 2019	$ 451,015,519	$ 268,151,601	$ 504,170	$ 223,267,573	$ (41,226,357)	$ 262,040	$ 56,492
Beginning balance, shares at Dec. 31, 2019						26,203,935	5,649,240
Issuance of common stock (stock compensation plans)	376,828	376,539				$ 289
Issuance of common stock (stock compensation plans), shares						28,924
Share-based compensation	1,242,986	1,242,315				$ 671
Share-based compensation, Shares						67,087
Net (loss) income	3,731,121			3,731,121
Cash dividends declared	(5,363)			(5,363)
Grant of stock options		118,525		(118,525)
Other comprehensive (loss) income	3,199,840		3,199,840
Ending balance at Mar. 31, 2020	459,560,931	269,888,980	3,704,010	226,874,806	(41,226,357)	$ 263,000	$ 56,492
Ending balance, shares at Mar. 31, 2020						26,299,946	5,649,240
Beginning balance at Dec. 31, 2019	451,015,519	268,151,601	504,170	223,267,573	(41,226,357)	$ 262,040	$ 56,492
Beginning balance, shares at Dec. 31, 2019						26,203,935	5,649,240
Net (loss) income	38,246,897
Other comprehensive (loss) income	9,866,047
Ending balance at Sep. 30, 2020	504,068,676	281,917,193	10,370,217	252,679,717	(41,226,357)	$ 271,414	$ 56,492
Ending balance, shares at Sep. 30, 2020						27,141,361	5,649,240
Beginning balance at Mar. 31, 2020	459,560,931	269,888,980	3,704,010	226,874,806	(41,226,357)	$ 263,000	$ 56,492
Beginning balance, shares at Mar. 31, 2020						26,299,946	5,649,240
Issuance of common stock (stock compensation plans)	720,548	720,018				$ 530
Issuance of common stock (stock compensation plans), shares						52,964
Share-based compensation	2,491,744	2,490,136				$ 1,608
Share-based compensation, Shares						160,869
Net (loss) income	22,678,778			22,678,778
Cash dividends declared	(4,255,882)			(4,255,882)
Grant of stock options		76,354		(76,354)
Other comprehensive (loss) income	6,663,215		6,663,215
Ending balance at Jun. 30, 2020	487,859,334	273,175,488	10,367,225	245,221,348	(41,226,357)	$ 265,138	$ 56,492
Ending balance, shares at Jun. 30, 2020						26,513,779	5,649,240
Issuance of common stock (stock compensation plans)	273,915	273,689				$ 226
Issuance of common stock (stock compensation plans), shares						22,662
Share-based compensation	8,364,438	8,358,388				$ 6,050
Share-based compensation, Shares						604,920
Net (loss) income	11,836,998			11,836,998
Cash dividends declared	(4,269,001)			(4,269,001)
Grant of stock options		109,628		(109,628)
Other comprehensive (loss) income	2,992		2,992
Ending balance at Sep. 30, 2020	504,068,676	281,917,193	10,370,217	252,679,717	(41,226,357)	$ 271,414	$ 56,492
Ending balance, shares at Sep. 30, 2020						27,141,361	5,649,240
Beginning balance at Dec. 31, 2020	517,774,120	289,149,567	11,130,612	258,387,288	(41,226,357)	$ 276,518	$ 56,492
Beginning balance, shares at Dec. 31, 2020						27,651,774	5,649,240
Issuance of common stock (stock compensation plans)	419,788	419,454				$ 334
Issuance of common stock (stock compensation plans), shares						33,336
Share-based compensation	4,722,849	4,719,388				$ 3,461
Share-based compensation, Shares						346,124
Net (loss) income	10,529,848			10,529,848
Cash dividends declared	(5,000)			(5,000)
Grant of stock options		109,184		(109,184)
Other comprehensive (loss) income	(4,207,115)		(4,207,115)
Ending balance at Mar. 31, 2021	529,234,490	294,397,593	6,923,497	268,802,952	(41,226,357)	$ 280,313	$ 56,492
Ending balance, shares at Mar. 31, 2021						28,031,234	5,649,240
Beginning balance at Dec. 31, 2020	517,774,120	289,149,567	11,130,612	258,387,288	(41,226,357)	$ 276,518	$ 56,492
Beginning balance, shares at Dec. 31, 2020						27,651,774	5,649,240
Net (loss) income	19,981,906
Other comprehensive (loss) income	(4,305,451)
Ending balance at Sep. 30, 2021	538,133,416	303,844,499	6,825,161	268,346,629	(41,226,357)	$ 286,992	$ 56,492
Ending balance, shares at Sep. 30, 2021						28,699,165	5,649,240
Beginning balance at Mar. 31, 2021	529,234,490	294,397,593	6,923,497	268,802,952	(41,226,357)	$ 280,313	$ 56,492
Beginning balance, shares at Mar. 31, 2021						28,031,234	5,649,240
Issuance of common stock (stock compensation plans)	730,501	730,005				$ 496
Issuance of common stock (stock compensation plans), shares						49,613
Share-based compensation	7,318,421	7,313,031				$ 5,390
Share-based compensation, Shares						539,019
Net (loss) income	16,164,036			16,164,036
Cash dividends declared	(4,840,629)			(4,840,629)
Grant of stock options		69,995		(69,995)
Other comprehensive (loss) income	1,549,974		1,549,974
Ending balance at Jun. 30, 2021	550,156,793	302,510,624	8,473,471	280,056,364	(41,226,357)	$ 286,199	$ 56,492
Ending balance, shares at Jun. 30, 2021						28,619,866	5,649,240
Issuance of common stock (stock compensation plans)	292,548	292,302				$ 246
Issuance of common stock (stock compensation plans), shares						24,619
Share-based compensation	946,551	946,004				$ 547
Share-based compensation, Shares						54,680
Net (loss) income	(6,711,978)			(6,711,978)
Cash dividends declared	(4,902,188)			(4,902,188)
Grant of stock options		95,569		(95,569)
Other comprehensive (loss) income	(1,648,310)		(1,648,310)
Ending balance at Sep. 30, 2021	$ 538,133,416	$ 303,844,499	$ 6,825,161	$ 268,346,629	$ (41,226,357)	$ 286,992	$ 56,492
Ending balance, shares at Sep. 30, 2021						28,699,165	5,649,240