Acquisitions, Goodwill And Other Intangible Assets (Pro Forma Information) (Details) - CURT - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition
Net sales	$ 2,639,761	$ 2,735,378
Net income	$ 144,878	$ 147,878
Basic net income per common share (in dollars per share)	$ 5.80	$ 5.87
Diluted net income per common share (in dollars per share)	$ 5.77	$ 5.81