Stockholders' Equity (Schedule of Components of Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Comprehensive Income (Loss) [Line Items]
Unrealized gain (loss) on marketable securities, gross amount	$ 0	$ 0	$ 0
Unrealized gain (loss) on marketable securities, income tax (provision) benefit	0	0	(1)
Unrealized gain (loss) on marketable securities, net amount	0	0	(1)
Foreign currency translation, gross amount	(10)	(65)	162
Foreign currency translation, income tax (provision) benefit	(6)	5	12
Foreign currency translation, net amount	(16)	(60)	174
Gain (loss) on cash flow hedges, gross amount	(38)	(12)	0
Gain (loss) on cash flow hedges, income tax (provision) benefit	8	2	(1)
Gain (loss) on cash flow hedges, net amount	(30)	(10)	(1)
Pension and postretirement benefits, gross amount	(6)	1	7
Pension and postretirement benefits, income tax (provision) benefit	(1)	(1)	2
Pension and postretirement benefits, net amount	(7)	0	9
Total other comprehensive income (loss), gross amount	(54)	(76)	169
Total other comprehensive income (loss), income tax (provision) benefit	1	6	12
Total other comprehensive income (loss), net of tax	$ (53)	$ (70)	$ 181