CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (4,611)	$ (129,884)
Adjustments to reconcile net loss to net cash provided by operating activities:
Unrealized gains on commodity derivative contracts, net	(8,372)	(35,157)
Asset retirement accretion	567	298
Depreciation, depletion, and amortization	94,806	55,909
Share-based compensation, net of amounts capitalized to oil and gas properties	3,014	682
Deferred income taxes	(2,980)	168,917
Amortization of deferred financing costs	2,264	376
Change in operating assets and liabilities:
Accounts receivable - oil and gas sales	(26,032)	5,015
Accounts receivable - JIB and other	(7,739)	2,872
Other current assets	(2,147)	(3,491)
Accounts payable	(4,546)	(3,077)
Accrued liabilities	28,717	(2,371)
Other	(101)	(126)
Net cash provided by operating activities	72,840	59,963
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in property and equipment	(259,584)	(184,245)
Investment in acquired property	(621,748)
Net cash used in investing activities	(881,332)	(184,245)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from long-term borrowings	861,450	20,067
Repayment of long-term borrowings	(34,300)	(103,167)
Proceeds from issuance of mandatorily redeemable convertible preferred units		65,000
Repayment of mandatorily redeemable convertible preferred units		(65,000)
Proceeds from sale of common stock, net of initial public offering expenses of $6.1 million		213,839
Deferred financing costs	(24,646)	(2,112)
Repurchase of common stock	(605)
Net cash provided by financing activities	801,899	128,627
NET DECREASE (INCREASE) IN CASH AND CASH EQUIVALENTS	(6,593)	4,345
Cash and cash equivalents, beginning of period	18,878	7,344
Cash and cash equivalents, end of period	12,285	11,689
SUPPLEMENTAL INFORMATION:
Non-cash transactions - investments in property and equipment accrued - not paid	104,161	79,400
Cash paid for interest, net of capitalized interest of $14.9 million and $2.4 million, respectively	$ 19,494	$ 2,763