Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Total Stockholders Equity	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Non-Redeemable Noncontrolling Interests in Subsidiaries	Parent Company [Member]
Balance at beginning of period at Dec. 31, 2017		$ 722	$ 1	$ 60	$ 857	$ (199)	$ 3
Balance at beginning of period (in shares) at Dec. 31, 2017			122.0
Comprehensive income:
Net income		20			20
Other comprehensive income		14				14
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Nonredeemable Noncontrolling Interest		34			20	14
Effects of adoption of new accounting standards		15			14	1
Employee stock purchase and stock compensation plans		8		8
Employee stock purchase and stock compensation plans (in shares)			1.0
Repurchase of Company common stock		165		68	97
Repurchase of Company common stock (in shares)			(5.0)
Series A convertible preferred stock dividends		(12)			(12)
Balance at end of period at Mar. 31, 2018		602	$ 1	0	782	(184)	3
Balance at end of period (in shares) at Mar. 31, 2018			118.0
Balance at beginning of period at Dec. 31, 2017		722	$ 1	60	857	(199)	3
Balance at beginning of period (in shares) at Dec. 31, 2017			122.0
Comprehensive income:
Other comprehensive income	$ (46)
Balance at end of period at Sep. 30, 2018		448	$ 1	19	666	(242)	4
Balance at end of period (in shares) at Sep. 30, 2018			118.0
Balance at beginning of period at Mar. 31, 2018		602	$ 1	0	782	(184)	3
Balance at beginning of period (in shares) at Mar. 31, 2018			118.0
Comprehensive income:
Net income		(145)			(145)
Other comprehensive income		(40)				(40)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Nonredeemable Noncontrolling Interest		(185)			(145)	(40)
Employee stock purchase and stock compensation plans		14		14
Employee stock purchase and stock compensation plans (in shares)			1.0
Repurchase of Company common stock		45		14	31
Repurchase of Company common stock (in shares)			(1.0)
Series A convertible preferred stock dividends		(12)			(12)
Balance at end of period at Jun. 30, 2018		374	$ 1	0	594	(224)	3
Balance at end of period (in shares) at Jun. 30, 2018			118.0
Comprehensive income:
Net income		84			84
Other comprehensive income	(17)	(17)				(18)	1
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Nonredeemable Noncontrolling Interest		67			84	(18)	1
Employee stock purchase and stock compensation plans		19		19
Series A convertible preferred stock dividends		(12)			(12)
Balance at end of period at Sep. 30, 2018		448	$ 1	19	666	(242)	4
Balance at end of period (in shares) at Sep. 30, 2018			118.0
Balance at beginning of period at Dec. 31, 2018	$ 399	399	$ 1	34	606	(246)	4	$ 395
Balance at beginning of period (in shares) at Dec. 31, 2018	118.7		119.0
Comprehensive income:
Net income		38			37		1
Other comprehensive income		16				16
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Nonredeemable Noncontrolling Interest		54			37	16	1
Employee stock purchase and stock compensation plans		14		14
Employee stock purchase and stock compensation plans (in shares)			1.0
Series A convertible preferred stock dividends		(13)			(13)
Balance at end of period at Mar. 31, 2019		454	$ 1	48	630	(230)	5
Balance at end of period (in shares) at Mar. 31, 2019			120.0
Balance at beginning of period at Dec. 31, 2018	$ 399	399	$ 1	34	606	(246)	4	395
Balance at beginning of period (in shares) at Dec. 31, 2018	118.7		119.0
Comprehensive income:
Other comprehensive income	$ (16)
Dividends paid to minority shareholder							(1)
Balance at end of period at Sep. 30, 2019	$ 731	731	$ 1	269	717	(261)	5	726
Balance at end of period (in shares) at Sep. 30, 2019	127.4		127.0
Balance at beginning of period at Mar. 31, 2019		454	$ 1	48	630	(230)	5
Balance at beginning of period (in shares) at Mar. 31, 2019			120.0
Comprehensive income:
Net income		88			88
Other comprehensive income		(11)				(11)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Nonredeemable Noncontrolling Interest		77			88	(11)
Employee stock purchase and stock compensation plans		28		28
Series A convertible preferred stock dividends		(12)			(12)
Balance at end of period at Jun. 30, 2019		547	$ 1	76	706	(241)	5
Balance at end of period (in shares) at Jun. 30, 2019			120.0
Comprehensive income:
Net income		91			90		1
Other comprehensive income	$ (21)	(20)				(20)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Nonredeemable Noncontrolling Interest		71			90	(20)	1
Employee stock purchase and stock compensation plans		17		17
Employee stock purchase and stock compensation plans (in shares)			1.0
Redemption of Preferred Shares		(205)		(272)	(67)
Repurchase of Company common stock		(96)		(96)
Repurchase of Company common stock (in shares)			(3.0)
Series A convertible preferred stock dividends		(12)			(12)
Series A convertible preferred stock converted into common stock			9.0
Dividends paid to minority shareholder		(1)
Balance at end of period at Sep. 30, 2019	$ 731	$ 731	$ 1	$ 269	$ 717	$ (261)	$ 5	$ 726
Balance at end of period (in shares) at Sep. 30, 2019	127.4		127.0