Significant Accounting Policies Activity in Polaris Accrued Warranty Reserve (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Activity in Product Warranty Reserve [Roll Forward]
Balance at beginning of period	$ 45,099	$ 44,811	$ 53,104	$ 52,818
Additions to warranty reserve through acquisitions	0	0	200	110
Additions charged to expense	25,288	21,227	53,853	44,524
Warranty claims paid	(15,290)	(14,644)	(52,060)	(46,058)
Balance at end of period	$ 55,097	$ 51,394	$ 55,097	$ 51,394