Consolidated Statements of Operations (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Interest income	$ 2	$ 1	$ 3	$ 2
Income from operations, tax (benefit) expense	3	15	27	33
Tax (benefit) expense on loss of dispositions from discontinued operations	$ (3)	$ (4)	$ (5)	$ (6)