Employee Benefit Plans - MEC - Employer Contributions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected contributions in current fiscal year	$ 4
Employer contributions	3
MEC | Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected contributions in current fiscal year	3
Employer contributions	1
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected contributions in current fiscal year	13
Employer contributions	4
U.S. | MEC | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected contributions in current fiscal year	7
Employer contributions	$ 2