Stockholders' Equity (Schedule of Components of Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Foreign currency translation gain (loss), gross amount	$ (4)	$ (31)	$ (3)	$ (58)
Foreign currency translation gain (loss), income tax (provision) benefit	(3)	(4)	(8)	6
Foreign currency translation gain (loss), net	(7)	(35)	(11)	(52)
Gain (loss) on cash flow hedges, gross amount	(33)	4	(55)	8
Gain (loss) on cash flow hedges, income tax (provision) benefit	1	0	7	1
Gain (loss) on cash flow hedges, net	(32)	4	(48)	9
Pension and postretirement benefits gain (loss), gross amount	0	0	0	1
Pension and postretirement benefits gain (loss), income tax (provision) benefit	0	0	0	0
Pension and postretirement benefits gain (loss), net	0	0	0	1
Other Comprehensive Income (Loss), before Tax	(37)	(27)	(58)	(49)
Income tax (provision) benefit	(2)	(4)	(1)	7
Total other comprehensive income (loss), net of tax	$ (39)	$ (31)	$ (59)	$ (42)