Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Revenue	$ 405,567,786	$ 368,937,455
Income from operations	120,848,990	107,708,506
Automotive Products
Segment Reporting Information [Line Items]
Revenue	393,968,947	360,615,289
Income from operations	115,980,617	104,808,058
Other
Segment Reporting Information [Line Items]
Revenue	11,598,839	8,322,166
Income from operations	$ 4,868,373	$ 2,900,448