CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 194	$ 252
Accounts receivable, less allowance for doubtful accounts of $2,368 and $2,374	152,670	167,495
Assets held for sale	165,478
Deferred tax asset	12,646
Unrealized derivative gain	23,052	137,552
Inventory and other	16,600	22,315
Total current assets	370,640	327,614
Unrealized derivative gain	4,387	15,715
Equity method investments	129,954	132,449
Natural gas and oil properties, successful efforts method	8,128,200	8,111,775
Accumulated depletion and depreciation	(1,944,252)	(2,015,591)
Natural gas and oil properties, successful efforts method, net	6,183,948	6,096,184
Transportation and field assets	116,448	117,717
Accumulated depreciation and amortization	(78,149)	(76,150)
Transportation and field assets, net	38,299	41,567
Other assets	139,303	115,206
Total assets	6,866,531	6,728,735
Current liabilities:
Accounts payable	363,273	234,651
Asset retirement obligations	2,366	2,470
Liabilities held for sale	8,346
Accrued liabilities	175,338	139,379
Deferred tax liability		37,924
Accrued interest	38,678	36,248
Unrealized derivative loss	19,662	4,471
Total current liabilities	607,663	455,143
Bank debt	47,000	739,000
Subordinated notes	2,889,505	2,139,185
Deferred tax liability	683,857	698,302
Unrealized derivative loss	8,370	3,463
Deferred compensation liability	222,700	187,604
Asset retirement obligations and other liabilities	150,044	148,646
Total liabilities	4,609,139	4,371,343
Commitments and contingencies
Preferred stock, $1 par, 10,000,000 shares authorized, none issued and outstanding
Common stock, $0.01 par, 475,000,000 shares authorized, issued at March 31, 2013 and 162,641,896 issued at December 31, 2012	1,630	1,626
Common stock held in treasury, shares at March 31, 2013 and 127,798 shares at December 31, 2012	(3,767)	(4,760)
Additional paid-in capital	1,924,619	1,915,627
Retained earnings	278,859	360,990
Accumulated other comprehensive income	56,051	83,909
Total stockholders' equity	2,257,392	2,357,392
Total liabilities and stockholders' equity	$ 6,866,531	$ 6,728,735