Retirement Plans - Contributions to Multiemployer Pension Plans (Parenthetical) (Detail)	12 Months Ended
Dec. 30, 2017
Minimum [Member]
Multiemployer Plans [Line Items]
Minimum Contribution by the employer to multi-employer plans as percentage of total contribution	5.00%

Percentage of contributions required by collective bargaining arrangement to all contributions required of employer for pension and other postretirement plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

Name:	us-gaap_MultiemployerPlanCollectiveBargainingArrangementRequiredPercentageOfContributions
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration