Partnership Capital - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018	Dec. 31, 2018	Jan. 12, 2018	Dec. 31, 2017
Partners Capital Account [Line Items]
Period of loans made by Partnership to general partners	1 year
Outstanding amount of partner loans financed through the Partnership	$ 373	$ 349	$ 373	$ 349	$ 332		$ 297
Interest income from outstanding amount of general partner loan	$ 5	5	$ 16	13
Limited partnership's minimum annual payment rate	7.50%		7.50%
Limited partnership's minimum return, value	$ 24	$ 17	$ 71	$ 50
2018 Limited Partnership Offering [Member]
Partners Capital Account [Line Items]
Limited partnership amount registered						$ 450
Limited partnership interests issued	380		380
Remaining limited partnership interests that may be issued	$ 70		$ 70