Retirement Plans - Amounts Recognized In The Balance Sheets (Details) - USD ($) $ in Millions	Jan. 02, 2021	Jan. 04, 2020
Pension Benefits
Amounts recognized in our balance sheets
Non-current assets	$ 216	$ 152
Current liabilities	(28)	(27)
Non-current liabilities	(941)	(934)
Recognized in Accumulated other comprehensive loss, pre-tax:
Net loss (gain)	2,238	2,271
Prior service cost (credit)	52	55
Postretirement Benefits Other than Pensions
Amounts recognized in our balance sheets
Non-current assets	0	0
Current liabilities	(23)	(26)
Non-current liabilities	(207)	(220)
Recognized in Accumulated other comprehensive loss, pre-tax:
Net loss (gain)	(23)	(21)
Prior service cost (credit)	$ (15)	$ (20)