Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Income from operations of discontinued businesses, income tax expense (benefit)	$ 0	$ 23	$ 24
Gain (loss) from disposal and impairment of discontinued businesses, income tax expense (benefit)	$ 0	$ 4	$ (15)