CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY/UNIT HOLDINGS EQUITY (USD $) In Thousands, unless otherwise specified	Total	Convertible preferred units	Series C Convertible preferred units	Common Units	Common Shares	Additional Paid-in Capital	Additional Paid-in Capital Convertible preferred units	Additional Paid-in Capital Series C Convertible preferred units	Accumulated Deficit	Accumulated Deficit Convertible preferred units	Accumulated Other Comprehensive Income	Treasury Stock
Balance at Dec. 31, 2008	$ (153,333)			$ 266		$ 4,134			$ (157,733)
Balance (in shares) at Dec. 31, 2008				16,172
Increase (Decrease) in Shareholders' Equity
Issuance of profit units (in shares)				10
Relinquishments of profit units (in shares)				(15)
Issuance of C1 units	11,756			250		11,506
Issuance of C1 units (in shares)				2,500
Equity-based compensation	3,468					3,468
Net income (loss)	(79,747)								(79,747)
Balance at Dec. 31, 2009	(217,856)			516		19,108			(237,480)
Balance (in shares) at Dec. 31, 2009				18,667
Increase (Decrease) in Shareholders' Equity
Issuance of profit units (in shares)				411
Relinquishments of profit units (in shares)				(8)
Accrete convertible preferred units to redemption amount		(153,506)	(11,756)				(21,143)	(11,756)		(132,363)
Equity-based compensation	13,791					13,791
Derivatives, net	588										588
Net income (loss)	(245,672)								(245,672)
Balance at Dec. 31, 2010	(614,411)			516					(615,515)		588
Balance (in shares) at Dec. 31, 2010				19,070
Increase (Decrease) in Shareholders' Equity
Issuance of profit units (in shares)				1,783
Relinquishments of profit units (in shares)				(2,686)
Accrete convertible preferred units to redemption amount		(24,442)					(1,452)			(22,990)
Common and restricted shares issued upon corporate reorganization	1,002,948			(516)	3,412	1,000,052
Common and restricted shares issued upon corporate reorganization (in shares)				(18,167)	341,177
Common shares issued at initial public offering, net of offering costs	580,374				345	580,029
Common shares issued at initial public offering, net of offering costs (in shares)					34,518
Equity-based compensation	50,966					50,966
Derivatives, net	2,934										2,934
Restricted stock awards					148	(148)
Restricted stock awards (in shares)					14,836
Restricted stock forfeitures						6						(6)
Net income (loss)	22,357								22,357
Balance at Dec. 31, 2011	$ 1,020,726			$ 0	$ 3,905	$ 1,629,453			$ (616,148)		$ 3,522	$ (6)
Balance (in shares) at Dec. 31, 2011				0	390,531