Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7	$ 7
Interest cost	19	20
Expected return on plan assets	(27)	(33)
Settlement	2	0
Net amortization	4	6
Net periodic benefit cost (credit)	5	0
Pension Plan | U.S. | MEC
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5
Interest cost	5	6
Expected return on plan assets	(7)	(9)
Settlement	2	0
Net periodic benefit cost (credit)	5	2
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	5	5
Expected return on plan assets	(7)	(5)
Net amortization	0	(1)
Net periodic benefit cost (credit)	0	1
Other Postretirement Plans | MEC
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	2	2
Expected return on plan assets	(4)	(2)
Net amortization	0	(1)
Net periodic benefit cost (credit)	$ 0	$ 1