Marketable Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 126	$ 160
Unrealized Gain (Loss)	0	2
Fair Value	126	162
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	34	38
Unrealized Gain (Loss)	0	0
Fair Value	34	38
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	42	42
Unrealized Gain (Loss)
Fair Value	42	42
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	24	18
Unrealized Gain (Loss)
Fair Value	24	18
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	26	62
Unrealized Gain (Loss)		2
Fair Value	$ 26	$ 64