CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Millions	Total	Common Shares ($1 par value)	Paid-In Capital	Retained (Deficit) Earnings	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Cumulative effect of adoption of new revenue recognition accounting standard | Accounting Standards Update 2014-09	$ 6			$ 6
Balance at Dec. 31, 2016	(103)	$ 318	$ 0	(381)	$ (235)	$ 195
Balance (Accounting Standards Update 2014-09) at Dec. 31, 2016	(97)	318	0	(375)	(235)	195
Increase (Decrease) in Stockholders' Equity
Total comprehensive income	620			453	108	59
Shares issued	(14)	2	(16)
Shares retired:
Repurchased	(312)	(8)	(6)	(298)
Surrendered (non-cash)	(15)	(1)		(14)
Cash dividends declared	(96)			(96)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(35)					(35)
Stock-based compensation	22		22
Balance at Sep. 30, 2017	73	311	0	(330)	(127)	219
Increase (Decrease) in Stockholders' Equity
Cumulative effect of adoption of new revenue recognition accounting standard | Accounting Standards Update 2018-02	0			59	(59)
Balance at Dec. 31, 2017	183	310	0	(298)	(65)	236
Increase (Decrease) in Stockholders' Equity
Total comprehensive income	575			540	11	24
Shares issued	(11)	2	(5)	(8)
Shares retired:
Repurchased	(354)	(9)	(18)	(327)
Surrendered (non-cash)	(19)			(19)
Cash dividends declared	(101)			(101)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(89)					(89)
Stock-based compensation	23		23
Balance at Sep. 30, 2018	$ 207	$ 303	$ 0	$ (154)	$ (113)	$ 171