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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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+ 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=26872669&loc=d3e20235-122688

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