CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 9,554	$ 23,474
Accounts receivable, net of allowance for doubtful accounts	167,190	194,403
Derivative assets	65	3,830
Deferred Tax Assets, Net of Valuation Allowance, Current	6,065	6,065
Other current assets	5,372	5,924
Total current assets	188,246	233,696
Property and equipment, net (successful efforts method)	2,312,003	2,237,304
Derivative assets	1,974	1,552
Other assets	33,710	34,535
Total assets	2,535,933	2,507,087
Current liabilities
Accounts payable and accrued liabilities	238,212	248,004
Derivative liabilities	19,403	10,141
Accrued Income Taxes, Current	200	0
Total current liabilities	257,815	258,145
Other liabilities	45,045	33,386
Derivative liabilities	0	0
Deferred income taxes	159,830	145,752
Long-term debt	1,265,000	1,281,000
Commitments and contingencies (Note 11)
Shareholders’ equity:
Preferred stock of $100 par value – 100,000 shares authorized; 11,481 and 11,500 shares issued as of March 31, 2014 and December 31, 2013, respectively, with a redemption value of $10,000 per share	1,148	1,150
Common stock of $0.01 par value – 128,000,000 shares authorized; 65,581,512 and 65,306,748 shares issued as of March 31, 2014 and December 31, 2013, respectively	468	466
Paid-in capital	893,262	891,351
Accumulated deficit	(86,677)	(104,180)
Deferred compensation obligation	2,897	2,792
Accumulated other comprehensive income	292	267
Treasury stock – 239,065 and 233,063 shares of common stock, at cost, as of March 31, 2014 and December 31, 2013, respectively	(3,147)	(3,042)
Total shareholders’ equity	808,243	788,804
Total liabilities and shareholders’ equity	$ 2,535,933	$ 2,507,087