Income Taxes - Components of Deferred Income Tax (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Net operating loss (NOL) carryforwards	$ 226	$ 183
Lease liabilities	277	257
Asset retirement obligation	101	81
Other	157	109
Total deferred tax assets	761	630
Less valuation allowance	(149)	(158)
Net deferred tax assets	612	472
Deferred tax liabilities
Property, plant and equipment	751	652
Licenses/intangibles	364	287
Partnership investments	155	144
Lease assets	255	235
Other	6	17
Total deferred tax liabilities	1,531	1,335
Net deferred income tax liability	919	863
Other assets and deferred charges
Deferred tax liabilities
Net deferred income tax liability	(2)	0
Deferred income tax liability, net
Deferred tax liabilities
Net deferred income tax liability	$ 921	$ 863