Employee Benefit Plans - Percentage Allocation of Plan Assets (Details) - Pension Benefits [Member]	Sep. 30, 2017	Sep. 24, 2016
Actual allocation of assets held in trust [Abstract]
Percentage allocation of plan assets	100.00%	100.00%
Fixed income securities [Member]
Actual allocation of assets held in trust [Abstract]
Percentage allocation of plan assets	85.00%	85.00%
Equity securities [Member]
Actual allocation of assets held in trust [Abstract]
Percentage allocation of plan assets	15.00%	15.00%

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant