Accumulated Other Comprehensive Income AOCI by Component (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Beginning Balance	$ 353	$ 98
Other comprehensive income (loss), net before reclassifications	6	0
Reclassification from AOCI, Current Period, Tax		(1)
Ending Balance	361	100
Equity Method Investments
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Beginning Balance	(3)	(3)
Other comprehensive income (loss), net before reclassifications	6	0
Reclassification from AOCI, Current Period, Tax		0
Ending Balance	3	(3)
Pension and Retiree Health and Welfare Benefit Items
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Beginning Balance	356	101
Other comprehensive income (loss), net before reclassifications	0	0
Reclassification from AOCI, Current Period, Tax		(1)
Ending Balance	358	103
Amortization of net loss
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Amortization of actuarial losses	2	3
Amortization of net loss | Equity Method Investments
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Amortization of actuarial losses	0	0
Amortization of net loss | Pension and Retiree Health and Welfare Benefit Items
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Amortization of actuarial losses	$ 2	$ 3