Guarantor Financial Information (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Condensed consolidating financial statements
Current assets	$ 150,061	$ 138,311
Property and equipment, net	1,184,247	1,199,107
Investments in subsidiaries	0	0
Other assets	28,522	29,319
Total assets	1,362,830	1,366,737	1,532,865
Current liabilities	156,371	136,395
Non-current liabilities:
Long-term debt	599,653	639,638
Deferred income taxes	146,076	140,809
Other	95,555	96,112
TOTAL NON-CURRENT LIABILITIES	841,284	876,559
Equity	365,175	353,783
Total liabilities and equity	1,362,830	1,366,737
Issuer
Condensed consolidating financial statements
Current assets	143,000	140,100
Property and equipment, net	821,503	833,980
Investments in subsidiaries	350,576	342,416
Other assets	15,197	16,032
Total assets	1,330,276	1,332,528
Current liabilities	311,081	290,327
Non-current liabilities:
Long-term debt	599,653	639,638
Deferred income taxes	121,918	118,438
Other	38,268	36,161
TOTAL NON-CURRENT LIABILITIES	759,839	794,237
Equity	259,356	247,964
Total liabilities and equity	1,330,276	1,332,528
Guarantor Subsidiaries
Condensed consolidating financial statements
Current assets	266,324	248,314
Property and equipment, net	347,368	351,171
Investments in subsidiaries	0	0
Other assets	13,325	13,287
Total assets	627,017	612,772
Current liabilities	98,052	93,055
Non-current liabilities:
Long-term debt	0	0
Deferred income taxes	134,054	129,880
Other	57,154	59,829
TOTAL NON-CURRENT LIABILITIES	191,208	189,709
Equity	337,757	330,008
Total liabilities and equity	627,017	612,772
Non-Guarantor Subsidiaries
Condensed consolidating financial statements
Current assets	605	538
Property and equipment, net	15,376	13,956
Investments in subsidiaries	0	0
Other assets	0	0
Total assets	15,981	14,494
Current liabilities	1,221	976
Non-current liabilities:
Long-term debt	0	0
Deferred income taxes	1,808	988
Other	133	122
TOTAL NON-CURRENT LIABILITIES	1,941	1,110
Equity	12,819	12,408
Total liabilities and equity	15,981	14,494
Adjustments/Eliminations
Condensed consolidating financial statements
Current assets	(259,868)	(250,641)
Property and equipment, net	0	0
Investments in subsidiaries	(350,576)	(342,416)
Other assets	0	0
Total assets	(610,444)	(593,057)
Current liabilities	(253,983)	(247,963)
Non-current liabilities:
Long-term debt	0	0
Deferred income taxes	(111,704)	(108,497)
Other	0	0
TOTAL NON-CURRENT LIABILITIES	(111,704)	(108,497)
Equity	(244,757)	(236,597)
Total liabilities and equity	$ (610,444)	$ (593,057)