Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenue	$ 288,621,626	$ 268,248,089	$ 845,094,493	$ 839,210,399
Income (loss) from operations	73,656,246	57,623,355	209,106,156	180,636,550
Assets	1,697,128,163		1,697,128,163		1,265,691,335
Automotive Products [Member]
Segment Reporting Information [Line Items]
Revenue	280,924,112	261,910,519	823,681,484	822,415,871
Income (loss) from operations	71,376,726	56,193,764	203,997,815	178,803,882
Assets	1,298,851,069		1,298,851,069		619,337,527
Other [Member]
Segment Reporting Information [Line Items]
Revenue	7,697,514	6,337,570	21,413,009	16,794,528
Income (loss) from operations	2,279,520	1,429,591	5,108,341	1,832,668
Assets	9,539,297		9,539,297		8,010,779
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 388,737,797		$ 388,737,797		$ 638,343,029