Retirement Plans - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 01, 2022	Jan. 02, 2021	Jan. 04, 2020
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	$ 9,947	$ 9,080	$ 8,129
Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	5,538	5,092
Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	1,335	1,443
Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	599	458
Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	2,475	2,087
Cash and equivalents | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	42	49
Cash and equivalents | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	6	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	158	132
Domestic equity securities | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	2,774	2,573
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	271	259
International equity securities | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	1,772	1,666
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	305	290
Mutual funds | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	123	195
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	677	482
National, state and local governments | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	274	306
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	98	95
Corporate debt | Level 1 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	150	127
Corporate debt | Level 2 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	1,055	1,134
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	170	178
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	1,098	819
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	599	458	$ 473
Real estate | Level 3 | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	599	458
Real estate | Not Subject to Leveling | Pension Benefits
Change in fair value of plan assets
Fair value of total pension plan assets	$ 375	$ 314