Partnership Capital Subject to Mandatory Redemption - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Dec. 31, 2020	Dec. 31, 2019	Jan. 12, 2018
Partners Capital Account [Line Items]
Period of loans made by Partnership to general partners			1 year		1 year
Percentage of interest made by partnership to general partners			3.25%		3.25%
Outstanding amount of partner loans financed through the Partnership	$ 395	$ 388	$ 395	$ 388	$ 341	$ 360
Interest income from outstanding amount of general partner loan	$ 4	$ 3	$ 7	$ 8
Limited partnership's minimum annual return rate	7.50%	7.50%	7.50%	7.50%
Limited partnership's minimum return, value	$ 23	$ 24	$ 46	$ 47
2018 Limited Partnership Offering [Member]
Partners Capital Account [Line Items]
Limited partnership amount registered							$ 450
Limited partnership interests issued	5		5		$ 1
Remaining limited partnership interests that may be issued	$ 64		$ 64