ADDITIONAL FINANCIAL STATEMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Accounts receivable:
Oil, natural gas and natural gas liquids revenues	$ 169,348	$ 129,355
Joint interest accounts	107,383	170,907
Affiliated partnership	46	500
Other	4,805	11,756
Total	281,582	312,518
Prepaids and other:
Prepaids	7,484	5,636
Income tax receivable	6,815	10,404
Other	571	58
Total	14,870	16,098
Accounts payable and accrued liabilities:
Trade payables	85,121	87,661
Accrued oil and natural gas capital costs	302,874	292,472
Revenues and royalties payable	165,414	124,222
Accrued interest expense	74,871	82,570
Accrued employee compensation	14,879	2,272
Accrued lease operating expense	24,197	21,469
Drilling advances from partners	29,650	24,882
Affiliated partnership	748	679
Other	316	362
Total	$ 698,070	$ 636,589