Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
CURRENT ASSETS
Cash and cash equivalents	$ 3,847	$ 52,095
Accounts receivable, net	119,851	112,821
Accounts receivable - related party	7,717	9,815
Current assets held for sale	0	1,882
Assets of discontinued operations	6,875	0
Fair value of derivative instruments	14,091	23,981
Prepaids and other current assets	7,562	8,111
Total current assets	159,943	208,705
Oil and gas properties using the full cost method of accounting
Proved oil and gas properties, net	1,429,801	1,152,548
Unproved properties, not being amortized	360,534	323,688
Other property and equipment, net	12,527	11,438
TOTAL PROPERTY AND EQUIPMENT, NET	1,802,862	1,487,674
LONG-TERM ASSETS HELD FOR SALE	0	132,626
DEFERRED FINANCING COSTS, NET	22,739	23,914
FAIR VALUE OF DERIVATIVE INSTRUMENTS	18,235	5,180
DEFERRED INCOME TAXES	0	21,272
OTHER ASSETS	6,518	4,625
TOTAL ASSETS	2,010,297	1,883,996
CURRENT LIABILITIES
Accounts payable, trade	96,428	44,775
Revenue and royalties payable	124,111	82,300
Accrued drilling costs	66,193	60,729
Accrued interest	17,502	18,012
Other accrued liabilities	36,435	28,445
Advances for joint operations	18,414	8,069
Deferred income taxes	1,284	7,925
Current liabilities associated with assets held for sale	0	48,663
Liabilities of discontinued operations	9,936	0
Total current liabilities	370,303	298,918
LONG-TERM DEBT, NET OF DEBT DISCOUNT	927,904	967,808
LONG-TERM LIABILITIES ASSOCIATED WITH ASSETS HELD FOR SALE	0	23,547
LIABILITIES OF DISCONTINUED OPERATIONS	17,999	0
ASSET RETIREMENT OBLIGATIONS	6,499	4,489
DEFERRED INCOME TAXES	24,763	0
OTHER LIABILITIES	4,577	4,218
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS’ EQUITY
Common stock, $0.01 par value (90,000 shares authorized, 40,864 and 40,165 shares issued and outstanding at June 30, 2013 and December 31, 2012, respectively)	409	402
Additional paid-in capital	677,173	667,096
Accumulated deficit	(19,330)	(82,482)
Total shareholders’ equity	658,252	585,016
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 2,010,297	$ 1,883,996