CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 30,387	$ 79,780
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	175,481	162,644
Accretion expense	15,288	16,581
Deferred income tax provision	18,094	56,422
Settlement of asset retirement obligations	(24,915)	(37,335)
Non-cash stock compensation expense	5,358	4,866
Excess tax benefits		(104)
Non-cash derivative expense	2,697	311
Non-cash interest expense	8,229	8,181
Change in current income taxes	(6)	(16,399)
(Increase) decrease in accounts receivable	(25,524)	1,138
Increase in other current assets	(82)	(245)
Decrease in inventory		158
Increase in accounts payable	1,843	6,593
Increase (decrease) in other current liabilities	50,785	(3,170)
Other	(675)	(3,448)
Net cash (used in) provided by operating activities	256,960	275,973
Cash flows from investing activities:
Investment in oil and gas properties	(517,904)	(320,218)
Proceeds from sale of oil and gas properties, net of expenses	51,955
Investment in fixed and other assets	(3,896)	(1,711)
Change in restricted funds	(356)	(3,515)
Net cash used in investing activities	(470,201)	(325,444)
Cash flows from financing activities:
Net proceeds from issuance of common stock	226,036
Deferred financing costs	(3,167)	(11)
Excess tax benefits		104
Net payments for share-based compensation	(6,948)	(3,590)
Net cash provided by (used in) financing activities	215,921	(3,497)
Effect of exchange rate changes on cash	(18)	(186)
Net change in cash and cash equivalents	2,662	(53,154)
Cash and cash equivalents, beginning of period	331,224	279,526
Cash and cash equivalents, end of period	$ 333,886	$ 226,372