Income Taxes Income Taxes (Schedule of Deferred Tax Assets and Related Valuation Allowance Recognized for Net Operating and Other Loss Carryforwards and Tax Carryforwards) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Deferred tax assets, tax credit carryforwards	$ 1,784	$ 1,796
Valuation allowance, tax credit carryforwards	(737)
Net deferred tax assets, tax credit carryforwards	1,047
Deferred tax assets, federal and state tax carryforwards	183
Federal and state tax carryforwards valuation allowance	(100)
Net deferred tax assets federal and state tax carryforwards	83
Deferred tax liabilities, tax credit carryforwards	(1,139)
Valuation allowance, other net deferred tax liabilities	0
Deferred tax assets, gross, net of deferred tax liabilities	828
Deferred tax assets, valuation allowance	(837)	(1,057)
Deferred Tax Liabilities, Net	9	$ (300)
Foreign tax credits
Operating Loss Carryforwards [Line Items]
Deferred tax assets, tax credit carryforwards	1,433
Valuation allowance, tax credit carryforwards	(737)
Net deferred tax assets, tax credit carryforwards	696
General business tax credit carryforward
Operating Loss Carryforwards [Line Items]
Deferred tax assets, tax credit carryforwards	351
Valuation allowance, tax credit carryforwards	0
Net deferred tax assets, tax credit carryforwards	351
Federal jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	7
Operating loss carryforwards, valuation allowance	0
Net deferred tax assets operating loss carryforwards	7
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	176
Operating loss carryforwards, valuation allowance	(100)
Net deferred tax assets operating loss carryforwards	$ 76