CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Interest paid capitalized interest	$ 78	$ 54	$ 52
Cash acquired for Level 3 acquisition	$ 2,300	$ 0	$ 0