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Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 443,139,073 | $ 423,800,778 | $ 896,674,323 | $ 829,368,564
Income from operations | 125,864,514 | 128,745,721 | 260,291,634 | 249,594,711
Automotive Products |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 433,922,260 | 414,403,115 | 879,574,835 | 808,372,062
Income from operations | 123,222,811 | 125,571,809 | 255,727,768 | 241,552,426
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 9,216,813 | 9,397,663 | 17,099,488 | 20,996,502
Income from operations | $ 2,641,703 | $ 3,173,912 | $ 4,563,866 | $ 8,042,285

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