Retirement Plans - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2023	Dec. 31, 2022	Jan. 01, 2022
Change in fair value of plan assets
Valuation of owned properties period	3 years
Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	$ 8,413	$ 7,943	$ 9,947
Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	5,006	4,393
Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	753	905
Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	508	569
Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	2,146	2,076
Cash and equivalents | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	231	378
Cash and equivalents | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	1	3
Cash and equivalents | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Cash and equivalents | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Domestic equity securities | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	2,754	2,304
Domestic equity securities | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Domestic equity securities | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Domestic equity securities | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	299	225
International equity securities | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	1,061	1,171
International equity securities | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
International equity securities | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
International equity securities | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	281	230
Mutual funds | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	117	150
Mutual funds | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Mutual funds | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
National, state and local governments | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	679	332
National, state and local governments | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	142	239
National, state and local governments | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
National, state and local governments | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	88	27
Corporate debt | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	164	58
Corporate debt | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	610	663
Corporate debt | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Corporate debt | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	90	129
Private investment partnerships | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Private investment partnerships | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Private investment partnerships | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Private investment partnerships | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	1,000	1,070
Real estate | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Real estate | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	0	0
Real estate | Level 3
Change in fair value of plan assets
Fair value of total pension plan assets	508	569	$ 599
Real estate | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	508	569
Real estate | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	$ 388	$ 395