Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 2,538	$ 10,838
Accounts receivable, net	82,585	92,946
Derivative Asset, Current	160,801	171,101
Other current assets	3,505	3,736
Total current assets	249,429	278,621
Oil and gas properties, full cost method
Proved properties, net	2,192,286	2,086,727
Unproved properties, not being amortized	540,595	535,197
Other property and equipment, net	7,971	7,329
Total property and equipment, net	2,740,852	2,629,253
Derivative Asset, Noncurrent	31,327	43,684
Debt issuance costs	24,377	25,403
Other assets	5,246	4,515
Total Assets	3,051,231	2,981,476
Current liabilities
Accounts payable	94,241	106,819
Revenues and royalties payable	57,220	66,954
Accrued capital expenditures	84,654	106,149
Accrued interest	25,847	21,149
Liabilities of discontinued operations	4,590	4,405
Deferred Tax Liabilities, Net, Current	56,399	61,258
Other current liabilities	61,533	57,570
Total current liabilities	384,484	424,304
Long-term debt	1,251,587	1,351,346
Liabilities of discontinued operations	7,497	8,394
Deferred income taxes	70,820	77,349
Asset retirement obligations	12,896	12,187
Other liabilities	4,391	4,455
Liabilities	1,731,675	1,878,035
Commitments and contingencies
Shareholders’ equity
Common stock, $0.01 par value, 90,000,000 shares authorized; 51,450,731 issued and outstanding as of March 31, 2015 and 46,127,924 issued and outstanding as of December 31, 2014	515	461
Additional paid-in capital	1,152,707	915,436
Retained earnings	166,334	187,544
Total shareholders’ equity	1,319,556	1,103,441
Total Liabilities and Shareholders’ Equity	$ 3,051,231	$ 2,981,476