Pension Plan and Other Postretirement Benefits (Pension and Other Postretirement Benefit Costs) (Details) - Pension - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0
Interest cost	1	1
Expected return on plan assets	0	(1)
Amortization of net loss	0	0
Settlement loss	0	0
Net periodic benefit cost	$ 1	$ 0