Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock Shares	Common Stock Amount	Accumulated Other Comprehensive Loss	Retained Earnings	Noncontrolling Interests' Equity
Balance, shares at Dec. 31, 2012		75,556,272
Balance at Dec. 31, 2012			$ 841	$ (6)	$ 893	$ 2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances of common stock, net of issuance costs		2,365,000
Issuances of common stock, net of issuance costs			67
Shares issued pursuant to equity-based plans		164,287
Proceeds from issuance of shares pursuant to equity-based plans			1
Stock-based compensation			2	0	0	0
Dividends declared			0	0	(85)	0
Net income (loss)	$ 104		0	0	105	(1)
Other comprehensive income (loss)			0	1	0	0
Balance, shares at Dec. 31, 2013		78,085,559
Balance at Dec. 31, 2013			911	(5)	913	1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued pursuant to equity-based plans		142,780
Proceeds from issuance of shares pursuant to equity-based plans			1
Stock-based compensation			6	0	0	0
Dividends declared			0	0	(88)	0
Net income (loss)	174		0	0	175	(1)
Other comprehensive income (loss)			0	(2)	0	0
Balance, shares at Dec. 31, 2014		78,228,339
Balance at Dec. 31, 2014	1,911		918	(7)	1,000	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances of common stock, net of issuance costs		10,400,000
Issuances of common stock, net of issuance costs			271
Shares issued pursuant to equity-based plans		164,412
Proceeds from issuance of shares pursuant to equity-based plans			1
Stock-based compensation			6	0	0	0
Dividends declared			0	0	(102)	0
Net income (loss)	172		0	0	172	0
Other comprehensive income (loss)			0	(1)	0	0
Balance, shares at Dec. 31, 2015		88,792,751
Balance at Dec. 31, 2015	$ 2,258		$ 1,196	$ (8)	$ 1,070	$ 0