Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 453,535,250	$ 405,567,786
Income from operations	134,427,120	120,848,990
Automotive Products
Segment Reporting Information [Line Items]
Revenue	445,652,575	393,968,947
Income from operations	132,504,957	115,980,617
Other
Segment Reporting Information [Line Items]
Revenue	7,882,675	11,598,839
Income from operations	$ 1,922,163	$ 4,868,373