Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, Gross		$ 663,500	$ 663,200	$ 667,600	$ 659,900
Impairments	$ (270,300)		(270,300)
Accumulated goodwill impairment losses		(270,300)	(270,300)	(270,300)
Currency translation effect on foreign goodwill balances		(4,100)	3,300
Goodwill		393,200	392,900	397,300	659,900
ORV/Snowmobiles
Goodwill [Roll Forward]
Goodwill, Gross		72,900	72,200	72,900	72,000
Currency translation effect on foreign goodwill balances		0	200
Goodwill		72,900	72,200	72,900	72,000
Motorcycles
Goodwill [Roll Forward]
Goodwill, Gross		5,200	5,200	5,200	5,200
Goodwill		5,200	5,200	5,200	5,200
Global Adjacent Markets
Goodwill [Roll Forward]
Goodwill, Gross		88,000	88,400	92,100	85,200
Currency translation effect on foreign goodwill balances		(4,100)	3,200
Goodwill		88,000	88,400	92,100	85,200
Aftermarket
Goodwill [Roll Forward]
Goodwill, Gross		270,300	270,300	270,300	270,400
Impairments			(270,300)
Accumulated goodwill impairment losses		(270,300)	(270,300)	(270,300)
Currency translation effect on foreign goodwill balances			(100)
Goodwill		0	0	0	270,400
Boats
Goodwill [Roll Forward]
Goodwill, Gross		227,100	227,100	227,100	227,100
Goodwill		$ 227,100	$ 227,100	$ 227,100	$ 227,100