Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Goodwill By Reportable Segment) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Segment Reporting Information
Net balance – December 31, 2017	$ 124,183
Acquisitions – 2018	20,982
Other	2,126
Net balance – March 31, 2018	147,291
OEM Segment
Segment Reporting Information
Net balance – December 31, 2017	109,641
Acquisitions – 2018	17,785
Other	2,126
Net balance – March 31, 2018	129,552
Aftermarket Segment
Segment Reporting Information
Net balance – December 31, 2017	14,542
Acquisitions – 2018	3,197
Other	0
Net balance – March 31, 2018	$ 17,739