CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - 6 months ended Jun. 30, 2018 - USD ($) shares in Thousands, $ in Millions	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]	Total
Beginning balance at Dec. 31, 2017	$ 6	$ 4,933	$ 8,588	$ 8	$ (7,516)	$ 23	$ 6,042
Beginning balance, shares at Dec. 31, 2017	630,282				(196,964)
Equity roll forward
Adoption of new accounting standards			85	(5)			80
Consolidated net income			895			(1)	894
Other comprehensive income (loss), net of tax				(52)			(52)
Cash dividends			(406)				(406)
Equity-based compensation transactions, net of tax		2	4		$ 62		68
Equity-based compensation transaction, shares					1,624
Common stock repurchase program					$ (550)		(550)
Common stock repurchase program, shares					(6,568)
Divestiture of noncontrolling interest						(19)	(19)
Other, net						(1)	(1)
Other, net, shares					2
Ending balance at Jun. 30, 2018	$ 6	$ 4,935	$ 9,166	$ (49)	$ (8,004)	$ 2	$ 6,056
Ending balance, shares at Jun. 30, 2018	630,282				(201,906)