Guarantor/Non-Guarantor Condensed Consolidated Financial Statements - Statements of Operations (Unaudited) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues	$ 231,978	$ 153,349
Costs and expenses:
Operating costs	141,773	100,737
Depreciation and amortization	38,373	32,256
General and administrative	21,143	14,521
Intercompany leasing	0	0
Bad debt expense (recovery)	(91)	(84)
Impairment of equipment	1,032	0
Total costs and expenses	202,230	147,430
Income from operations	29,748	5,919
Other (expense) income:
Equity in earnings of subsidiaries	0	0
Interest expense	(9,555)	(7,539)
Other	932	(6,517)
Total other expense	(8,623)	(14,056)
Income (loss) before income taxes	21,125	(8,137)
Income tax (expense) benefit	(6,953)	2,102
Net income (loss)	14,172	(6,035)
Parent [Member]
Revenues	0	0
Costs and expenses:
Operating costs	0	0
Depreciation and amortization	165	275
General and administrative	5,508	4,131
Intercompany leasing	0	0
Bad debt expense (recovery)	0	0
Impairment of equipment	0
Total costs and expenses	5,673	4,406
Income from operations	(5,673)	(4,406)
Other (expense) income:
Equity in earnings of subsidiaries	23,550	807
Interest expense	(9,513)	(7,472)
Other	(68)	532
Total other expense	13,969	(6,133)
Income (loss) before income taxes	8,296	(10,539)
Income tax (expense) benefit	5,876	4,504
Net income (loss)	14,172	(6,035)
Guarantor Subsidiaries [Member]
Revenues	190,842	129,115
Costs and expenses:
Operating costs	114,941	81,878
Depreciation and amortization	32,689	29,118
General and administrative	13,032	9,890
Intercompany leasing	(1,215)	(1,215)
Bad debt expense (recovery)	(180)	(84)
Impairment of equipment	1,032
Total costs and expenses	160,299	119,587
Income from operations	30,543	9,528
Other (expense) income:
Equity in earnings of subsidiaries	4,648	(5,027)
Interest expense	(40)	(73)
Other	250	236
Total other expense	4,858	(4,864)
Income (loss) before income taxes	35,401	4,664
Income tax (expense) benefit	(11,851)	(3,857)
Net income (loss)	23,550	807
Non-Guarantor Subsidiaries [Member]
Revenues	41,136	24,234
Costs and expenses:
Operating costs	26,832	18,859
Depreciation and amortization	5,519	2,863
General and administrative	2,741	608
Intercompany leasing	1,231	1,215
Bad debt expense (recovery)	89	0
Impairment of equipment	0
Total costs and expenses	36,412	23,545
Income from operations	4,724	689
Other (expense) income:
Equity in earnings of subsidiaries	0	0
Interest expense	(2)	6
Other	904	(7,177)
Total other expense	902	(7,171)
Income (loss) before income taxes	5,626	(6,482)
Income tax (expense) benefit	(978)	1,455
Net income (loss)	4,648	(5,027)
Eliminations [Member]
Revenues	0	0
Costs and expenses:
Operating costs	0	0
Depreciation and amortization	0	0
General and administrative	(138)	(108)
Intercompany leasing	(16)	0
Bad debt expense (recovery)	0	0
Impairment of equipment	0
Total costs and expenses	(154)	(108)
Income from operations	154	108
Other (expense) income:
Equity in earnings of subsidiaries	(28,198)	4,220
Interest expense	0	0
Other	(154)	(108)
Total other expense	(28,352)	4,112
Income (loss) before income taxes	(28,198)	4,220
Income tax (expense) benefit	0	0
Net income (loss)	$ (28,198)	$ 4,220