Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Revenue	$ 286,973,898	$ 280,255,548	$ 556,472,867	$ 570,962,310
Income (loss) from operations	71,596,271	57,512,232	135,449,910	123,013,195
Automotive Products [Member]
Segment Reporting Information [Line Items]
Revenue	279,789,872	274,820,852	542,757,372	560,505,352
Income (loss) from operations	69,959,655	57,139,415	132,621,089	122,610,118
Other [Member]
Segment Reporting Information [Line Items]
Revenue	7,184,026	5,434,696	13,715,495	10,456,958
Income (loss) from operations	$ 1,636,616	$ 372,817	$ 2,828,821	$ 403,077