Acquisitions - Unaudited Proforma Information (Details) - Boat Holdings, LLC - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Net sales	$ 1,771,647	$ 1,651,415	$ 5,046,652	$ 4,802,580
Net income	$ 89,478	$ 99,224	$ 228,004	$ 268,660
Basic earnings per share (in dollars per share)	$ 1.46	$ 1.60	$ 3.71	$ 4.27
Diluted earnings per common share (in dollars per share)	$ 1.44	$ 1.56	$ 3.67	$ 4.16