Segment Reporting (Schedule of Automotive and Other Segment Reporting) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 477,761,417	$ 460,253,433	$ 1,415,061,768	$ 1,380,654,978
Income from operations	128,135,680	127,427,911	377,636,979	382,626,248
Automotive Products
Segment Reporting Information [Line Items]
Revenue	464,280,707	449,184,447	1,376,704,413	1,348,395,245
Income from operations	123,342,538	124,351,499	364,590,462	373,071,852
Other
Segment Reporting Information [Line Items]
Revenue	13,480,710	11,068,986	38,357,355	32,259,733
Income from operations	$ 4,793,142	$ 3,076,412	$ 13,046,517	$ 9,554,396