Organization and Significant Accounting Policies - Activity in Polaris Accrued Warranty Reserve (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Activity in Product Warranty Reserve [Roll Forward]
Balance at beginning of year	$ 123,840	$ 119,274	$ 56,474
Additions to reserve through acquisitions	19,468	0	147
Additions charged to expense	105,015	145,705	194,996
Less: warranty claims paid	126,499	141,139	(132,343)
Balance at end of year	$ 121,824	$ 123,840	$ 119,274