Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	$ 5,860	$ 5,590
Accumulated Other Comprehensive Income (Loss), Net of Tax	(74)	(62)	$ 7
Reclassification of certain tax effects to retained earnings		0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	3	27	43
Other comprehensive income (loss) before reclassifications	(24)	(14)
Amounts reclassified from accumulated other comprehensive income (loss)	0	(11)
Reclassification of certain tax effects to retained earnings		9
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(24)	(16)
Accumulated Foreign Currency Adjustment Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(77)	(89)	$ (36)
Other comprehensive income (loss) before reclassifications	12	(57)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Reclassification of certain tax effects to retained earnings		4
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	12	(53)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	(12)	(71)
Amounts reclassified from accumulated other comprehensive income (loss)	0	(11)
Reclassification of certain tax effects to retained earnings		13
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (12)	$ (69)