Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Revenue	$ 338,436,964	$ 286,973,898	$ 674,176,308	$ 556,472,867
Income from operations	99,835,438	71,596,271	197,012,984	135,449,910
Automotive Products
Segment Reporting Information [Line Items]
Revenue	329,557,679	279,789,872	655,921,786	542,757,372
Income from operations	96,849,968	69,959,655	190,294,435	132,621,089
Other
Segment Reporting Information [Line Items]
Revenue	8,879,285	7,184,026	18,254,522	13,715,495
Income from operations	$ 2,985,470	$ 1,636,616	$ 6,718,549	$ 2,828,821