CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance at Dec. 31, 2012	$ 1,562	$ 1	$ 1,127	$ 372	$ 26	$ 36
Balance (in shares) at Dec. 31, 2012		56,975,991
Increase (Decrease) in Stockholders' Equity
Total comprehensive income (loss)	154			135	(10)	29
Distributions to noncontrolling interest	(41)					(41)
Stock compensation expense	9		9
Stock issued under share-based payment plans	2		2
Stock issued under share-based payment plans (in shares)		289,526
Recognition of deferred taxes related to Convertible notes	4		4
Balance at Dec. 31, 2013	1,690	$ 1	1,142	507	16	24
Balance (in shares) at Dec. 31, 2013		57,265,517
Increase (Decrease) in Stockholders' Equity
Total comprehensive income (loss)	60			81	(27)	6
Distributions to noncontrolling interest	(4)					(4)
Stock compensation expense	8		8
Stock issued under share-based payment plans	16		16
Stock issued under share-based payment plans (in shares)		840,901
Repurchase of common stock	(200)		(178)	(22)
Repurchase of common stock (in shares)		(6,962,695)
Conversion of Convertible notes	(4)		(4)
Recognition of deferred taxes related to Convertible notes	5		5
Balance at Dec. 31, 2014	$ 1,571	$ 1	989	566	(11)	26
Balance (in shares) at Dec. 31, 2014	51,143,723	51,143,723
Increase (Decrease) in Stockholders' Equity
Total comprehensive income (loss)	$ (130)			(145)	1	14
Distributions to noncontrolling interest	(10)					(10)
Stock compensation expense	9		9
Stock issued under share-based payment plans	2		2
Stock issued under share-based payment plans (in shares)		204,126
Repurchase of common stock	(78)	$ (1)	(72)	(5)
Repurchase of common stock (in shares)		(6,415,519)
Number of shares issued from conversion of notes (in shares)		10,075,653
Stock Issued During Period, Value, Conversion of Convertible Securities		$ 1
Conversion of Convertible notes	(18)		(19)
Recognition of deferred taxes related to Convertible notes	2		2
Balance at Dec. 31, 2015	$ 1,348	$ 1	$ 911	$ 416	$ (10)	$ 30
Balance (in shares) at Dec. 31, 2015	55,007,983	55,007,983