Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenue	$ 350,913,912	$ 288,621,626	$ 1,025,090,220	$ 845,094,493
Income from operations	103,205,827	73,656,246	300,218,811	209,106,156
Automotive Products
Segment Reporting Information [Line Items]
Revenue	341,786,404	280,924,112	997,708,190	823,681,484
Income from operations	100,053,622	71,376,726	290,348,056	203,997,815
Other
Segment Reporting Information [Line Items]
Revenue	9,127,508	7,697,514	27,382,030	21,413,009
Income from operations	$ 3,152,205	$ 2,279,520	$ 9,870,755	$ 5,108,341