Number of shares that have been repurchased and retired during the period.

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Name:	us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Stockholders' Equity and Noncontrolling Interests - Additional Information (Detail) - shares	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016	Nov. 30, 2016
Shareholders Equity [Line Items]
Number (in shares)	1,600,000	3,300,000	5,700,000
November 2016
Shareholders Equity [Line Items]
Number of shares authorized to be repurchased by VMS Board of Directors (in shares)				8,000,000.0
Number of shares remain available for repurchase (in shares)	3,600,000