Stockholders' Equity (Schedule of Components of Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		158 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021
Stockholders' Equity Note [Abstract]
Foreign currency translation gain (loss), gross amount	$ 3	$ 10
Foreign currency translation gain (loss), income tax (provision) benefit	(7)	(12)
Foreign currency translation gain (loss), net	(4)	(2)
Gain (loss) on cash flow hedges, gross amount	44	(51)
Gain (loss) on cash flow hedges, income tax (provision) benefit	(10)	12
Gain (loss) on cash flow hedges, net	34	(39)
Pension and postretirement benefits gain (loss), gross amount	(4)	0
Pension and postretirement benefits gain (loss), income tax (provision) benefit	0	0
Pension and postretirement benefits gain (loss), net	(4)	0
Other Comprehensive Income (Loss), before Tax	43	(41)
Income tax (provision) benefit	(17)	0
Total other comprehensive income (loss), net of tax	26	(41)
Aggregate Board of Directors repurchase authorizations (in $ millions)	$ 0	$ 0	$ 5,866