Lines of Credit - Composition of Partnership's Aggregate Bank Lines of Credit (Detail) - USD ($)	Sep. 28, 2018	Dec. 31, 2017	Nov. 29, 2013
Line of Credit Facility [Line Items]
Line of credit facility	$ 790,000,000	$ 690,000,000
2018 Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility	500,000,000
2013 Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility		400,000,000	$ 400,000,000
Uncommitted Secured Credit Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility	$ 290,000,000	$ 290,000,000