Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Retirement Benefits [Abstract]
Interest cost	$ (24)	$ (28)	$ (48)	$ (56)
Expected return on plan assets	42	39	84	77
Remeasurement gain, net	155	0	155	0
Net periodic pension benefits	$ 173	$ 11	$ 191	$ 21