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Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2016 | Jun. 30, 2015
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 423,800,778 | $ 379,258,477 | $ 829,368,564 | $ 748,195,932
Income from operations | 128,745,721 | 108,132,830 | 249,594,711 | 215,841,336
Automotive Products |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 414,403,115 | 370,504,300 | 808,372,062 | 731,119,589
Income from operations | 125,571,809 | 105,242,465 | 241,552,426 | 210,050,524
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 9,397,663 | 8,754,177 | 20,996,502 | 17,076,343
Income from operations | $ 3,173,912 | $ 2,890,365 | $ 8,042,285 | $ 5,790,812

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