CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 2,121	$ 1,056	$ 39,169	$ 3,012
Accounts receivable	63,734	67,516
Other current assets	25,366	56,508
Total current assets	91,221	125,080
Property and equipment, at cost	9,933,072	10,038,332
Less accumulated depreciation, depletion, and amortization	8,419,440	8,284,094
Net property and equipment	1,513,632	1,754,238
Investment in subsidiaries	0	0
Goodwill	239,420	239,420
Due from subsidiaries	0	0
Deferred income taxes	6,221	14,681
Other assets	58,823	68,443
TOTAL ASSETS	1,909,317	2,201,862
Current liabilities:
Accounts payable and accrued liabilities	189,362	164,786
Other current liabilities	50,159	61,539
Total current liabilities	239,521	226,325
Long-term debt	1,615,322	1,862,088
Due to parent and subsidiaries	0	0
Deferred income taxes	0	0
Other liabilities	117,564	156,273
Total liabilities	1,972,407	2,244,686
Shareholders' equity (deficit)	(63,090)	(42,824)
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	1,909,317	2,201,862
Parent Company
Current assets:
Cash and cash equivalents	770	667
Accounts receivable	38,415	33,979
Other current assets	24,957	55,869
Total current assets	64,142	90,515
Property and equipment, at cost	8,294,495	8,439,898
Less accumulated depreciation, depletion, and amortization	7,040,529	6,937,606
Net property and equipment	1,253,966	1,502,292
Investment in subsidiaries	104,137	68,048
Goodwill	216,460	216,460
Due from subsidiaries	85,994	116,602
Deferred income taxes	102,555	111,015
Other assets	58,823	68,443
TOTAL ASSETS	1,886,077	2,173,375
Current liabilities:
Accounts payable and accrued liabilities	182,633	157,404
Other current liabilities	44,694	55,187
Total current liabilities	227,327	212,591
Long-term debt	1,615,322	1,862,088
Due to parent and subsidiaries	0	0
Deferred income taxes	0	0
Other liabilities	106,518	141,520
Total liabilities	1,949,167	2,216,199
Shareholders' equity (deficit)	(63,090)	(42,824)
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	1,886,077	2,173,375
Guarantor Subsidiary
Current assets:
Cash and cash equivalents	56	45	0	1
Accounts receivable	23,273	27,969
Other current assets	292	286
Total current assets	23,621	28,300
Property and equipment, at cost	1,460,596	1,416,364
Less accumulated depreciation, depletion, and amortization	1,203,938	1,173,332
Net property and equipment	256,658	243,032
Investment in subsidiaries	0	0
Goodwill	22,960	22,960
Due from subsidiaries	111,080	83,983
Deferred income taxes	0	0
Other assets	0	0
TOTAL ASSETS	414,319	378,275
Current liabilities:
Accounts payable and accrued liabilities	1,305	2,133
Other current liabilities	0	67
Total current liabilities	1,305	2,200
Long-term debt	0	0
Due to parent and subsidiaries	0	0
Deferred income taxes	132,440	132,440
Other liabilities	3,682	3,642
Total liabilities	137,427	138,282
Shareholders' equity (deficit)	276,892	239,993
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	414,319	378,275
Combined Non-Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	1,295	344	71	1,277
Accounts receivable	2,645	6,393
Other current assets	117	353
Total current assets	4,057	7,090
Property and equipment, at cost	177,981	182,070
Less accumulated depreciation, depletion, and amortization	174,973	173,156
Net property and equipment	3,008	8,914
Investment in subsidiaries	0	0
Goodwill	0	0
Due from subsidiaries	0	0
Deferred income taxes	36,106	36,106
Other assets	0	0
TOTAL ASSETS	43,171	52,110
Current liabilities:
Accounts payable and accrued liabilities	6,023	6,074
Other current liabilities	5,465	6,285
Total current liabilities	11,488	12,359
Long-term debt	0	0
Due to parent and subsidiaries	197,074	200,585
Deferred income taxes	0	0
Other liabilities	7,364	11,111
Total liabilities	215,926	224,055
Shareholders' equity (deficit)	(172,755)	(171,945)
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	43,171	52,110
Eliminations
Current assets:
Cash and cash equivalents	0	0
Accounts receivable	(599)	(825)
Other current assets	0	0
Total current assets	(599)	(825)
Property and equipment, at cost	0	0
Less accumulated depreciation, depletion, and amortization	0	0
Net property and equipment	0	0
Investment in subsidiaries	(104,137)	(68,048)
Goodwill	0	0
Due from subsidiaries	(197,074)	(200,585)
Deferred income taxes	(132,440)	(132,440)
Other assets	0	0
TOTAL ASSETS	(434,250)	(401,898)
Current liabilities:
Accounts payable and accrued liabilities	(599)	(825)
Other current liabilities	0	0
Total current liabilities	(599)	(825)
Long-term debt	0	0
Due to parent and subsidiaries	(197,074)	(200,585)
Deferred income taxes	(132,440)	(132,440)
Other liabilities	0	0
Total liabilities	(330,113)	(333,850)
Shareholders' equity (deficit)	(104,137)	(68,048)
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ (434,250)	$ (401,898)