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Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 379,258,477 | $ 338,436,964 | $ 748,195,932 | $ 674,176,308
Income from operations | 108,132,830 | 99,835,438 | 215,841,336 | 197,012,984
Automotive Products |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 370,504,300 | 329,557,679 | 731,119,589 | 655,921,786
Income from operations | 105,242,465 | 96,849,968 | 210,050,524 | 190,294,435
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 8,754,177 | 8,879,285 | 17,076,343 | 18,254,522
Income from operations | $ 2,890,365 | $ 2,985,470 | $ 5,790,812 | $ 6,718,549

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