CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 6,252	$ 23,474
Accounts receivable, net of allowance for doubtful accounts	189,627	194,403
Derivative assets	128,981	3,830
Deferred income taxes	53	6,065
Other current assets	10,114	5,924
Total current assets	335,027	233,696
Property and equipment, net (successful efforts method)	1,825,098	2,237,304
Derivative assets	35,897	1,552
Other assets	30,412	34,535
Total assets	2,226,434	2,507,087
Current liabilities
Accounts payable and accrued liabilities	312,227	248,004
Derivative liabilities	0	10,141
Total current liabilities	312,227	258,145
Other liabilities	123,886	33,386
Deferred income taxes	4,504	145,752
Long-term debt	1,110,000	1,281,000
Commitments and contingencies (Note 12)
Shareholders’ equity:
Preferred stock of $100 par value – 100,000 shares authorized; Series A – 7,945 and 11,500 shares issued as of December 31, 2014 and December 31, 2013, respectively, and Series B – 32,500 shares issued as of December 31, 2014, each with a redemption value of $10,000 per share	4,044	1,150
Common stock of $0.01 par value – 128,000,000 shares authorized; shares issued of 71,568,936 and 65,306,748 as of December 31, 2014 and December 31, 2013, respectively	529	466
Paid-in capital	1,206,305	891,351
Accumulated deficit	(535,176)	(104,180)
Deferred compensation obligation	3,211	2,792
Accumulated other comprehensive income	249	267
Treasury stock – 262,070 and 233,063 shares of common stock, at cost, as of December 31, 2014 and December 31, 2013, respectively	(3,345)	(3,042)
Total shareholders’ equity	675,817	788,804
Total liabilities and shareholders’ equity	$ 2,226,434	$ 2,507,087