Consolidated Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Sep. 24, 2016	Sep. 26, 2015	Sep. 27, 2014
Statement of Comprehensive Income [Abstract]
Changes in pension plans, tax	$ 0.3	$ 0.3	$ 0.2
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	$ 2.0	$ 2.5	$ 0.0

Amount of tax (expense) benefit, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans, attributable to parent entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4569616-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4569643-111683

Name:	us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration