Significant Accounting Policies Activity in Polaris Accrued Warranty Reserve (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Activity in Product Warranty Reserve [Roll Forward]
Balance at beginning of period	$ 76,873	$ 45,099	$ 56,474	$ 53,104
Additions to warranty reserve through acquisitions	0	0	147	200
Additions charged to expense	87,679	25,288	155,210	53,853
Warranty claims paid	(34,498)	(15,290)	(81,777)	(52,060)
Balance at end of period	$ 130,054	$ 55,097	$ 130,054	$ 55,097