Acquisition - Additional Information (Detail) - USD ($) $ in Thousands		9 Months Ended
	Jun. 30, 2016	Apr. 30, 2017
Trademarks
Business Acquisition [Line Items]
Intangible assets amortization period		19 years
Jayco, Corp.
Business Acquisition [Line Items]
Payment to acquire business	$ 576,060
Asset purchase agreement date	Jun. 30, 2016
Asset purchase effective date	Jun. 30, 2016
Purchase price adjustment	$ 5,039
Amortizable intangible assets, weighted average useful life	19 years 3 months 18 days
Jayco, Corp. | Consideration Funded By Credit Facility
Business Acquisition [Line Items]
Borrowings on revolving credit facility	$ 360,000
Jayco, Corp. | Trademarks
Business Acquisition [Line Items]
Intangible assets amortization period	20 years
Amortizable intangible assets, amortization method		Straight-line basis
Jayco, Corp. | Backlog
Business Acquisition [Line Items]
Intangible assets amortization period	3 months
Amortizable intangible assets, amortization method		Straight-line basis
Jayco, Corp. | Dealer Networks
Business Acquisition [Line Items]
Intangible assets amortization period	20 years
Amortizable intangible assets, amortization method		Accelerated cash flow basis