Business Combinations - Additional Information (Detail) $ in Millions	2 Months Ended	3 Months Ended
	Nov. 17, 2018 USD ($) Business-Combination	Sep. 29, 2018 USD ($)	Sep. 30, 2017 USD ($)
Business Acquisition [Line Items]
Payment for acquisition		$ 31.5	$ 63.2
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of acquisitions | Business-Combination	1
Business Acquisition Cost [Member]
Business Acquisition [Line Items]
Payment for acquisition		$ 31.5	$ 63.4
Business Acquisition Cost [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Payment for acquisition	$ 24.9