Schedule I - Condensed Statements of Cash Flow (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 25, 2020	Jun. 26, 2020	Mar. 27, 2020	Dec. 31, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income									$ 0	$ 0	$ 0
Adjustments to reconcile net income to net cash provided by operating activities:
Income before allocations to partners	$ 378	$ 316	$ 288	$ 303	$ 285	$ 281	$ 285	$ 241	1,285	1,092	990
Changes in assets and liabilities:
Other assets									7	(14)	(14)
Accounts payable and accrued expenses									(31)	47	26
Net cash provided by operating activities									25	13	1,138
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of partnership interests									50	432	60
Redemption of partnership interests									(214)	(216)	(199)
Distributions from partnership capital									(864)	(783)	(694)
Net cash used in financing activities									(1,028)	(567)	(833)
Net (decrease) increase in cash, cash equivalents and restricted cash									(1,132)	(730)	200
CASH AND CASH EQUIVALENTS:
Beginning of year				8,007				8,737	8,007	8,737	8,537
End of year	6,875				8,007				6,875	8,007	8,737
NON-CASH ACTIVITIES:
Declared distributions for retired partnership capital in current year but unpaid at year end									145	113	97
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income									0	0	0
Adjustments to reconcile net income to net cash provided by operating activities:
Income before allocations to partners									1,285	1,092	990
Changes in assets and liabilities:
Investment in subsidiaries									(1)	(513)	(134)
Investment securities									(247)	5	0
Other assets									(6)	(16)	(14)
Accounts payable and accrued expenses									0	1	1
Net cash provided by operating activities									1,031	569	843
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of partnership interests									50	432	60
Redemption of partnership interests									(214)	(216)	(199)
Distributions from partnership capital									(864)	(783)	(694)
Net cash used in financing activities									(1,028)	(567)	(833)
Net (decrease) increase in cash, cash equivalents and restricted cash									3	2	10
CASH AND CASH EQUIVALENTS:
Beginning of year				$ 320				$ 318	320	318	308
End of year	$ 323				$ 320				323	320	318
NON-CASH ACTIVITIES:
Issuance of general partnership interests through partnership loans in current year									163	164	170
Repayment of partnership loans through distributions from partnership capital in current year									182	136	135
Declaration of distributions from subsidiary in current year but received after year end									474	428	56
Declared distributions for retired partnership capital in current year but unpaid at year end									$ 145	$ 109	$ 97