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Segment Reporting (Schedule Of Automotive And Other Segment Reporting) (Details) - USD ($) | 3 Months Ended
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Mar. 31, 2018 | Mar. 31, 2017
Segment Reporting Information [Line Items] |  |
Revenue | $ 465,420,105 | $ 453,535,250
Income from operations | 128,515,333 | 134,427,120
Automotive Products |  |
Segment Reporting Information [Line Items] |  |
Revenue | 454,965,374 | 445,652,575
Income from operations | 124,962,159 | 132,504,957
Other |  |
Segment Reporting Information [Line Items] |  |
Revenue | 10,454,731 | 7,882,675
Income from operations | $ 3,553,174 | $ 1,922,163

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- Definition Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1(a)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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