Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Operating loss carryforwards	$ 2,052	$ 2,006
Tax credit carryforwards	419	437
Property	156	127
Employee benefits	116	138
Goodwill and other intangibles	97	143
Receivables	72	53
Inventory	61	51
Other	125	233
Total deferred income tax asset	3,098	3,188
Valuation allowances	(2,432)	(2,342)
Total deferred income tax asset after valuation allowance	666	846
Deferred tax liabilities:
Other	(4)	(1)
Total deferred income tax liability	(4)	(1)
Net deferred tax asset	$ 662	$ 845