Pensions and Other Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2025	Mar. 31, 2024
Retirement Plans
Components of net periodic benefit cost
Service cost	$ 214	$ 224
Interest cost	351	352
Expected return on plan assets	(587)	(642)
Amortization of prior service cost/‍(credit)	(46)	(46)
Recognized actuarial (gains)/losses	83	43
Net periodic benefit cost/(credit)	15	(69)
Other Benefit Plans
Components of net periodic benefit cost
Service cost	72	69
Interest cost	54	52
Expected return on plan assets	(2)	(2)
Amortization of prior service cost/‍(credit)	0	0
Recognized actuarial (gains)/losses	16	13
Net periodic benefit cost/(credit)	$ 140	$ 132