Guarantor/Non-Guarantor Condensed Consolidated Financial Statements - Statements of Operations (Unaudited) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues	$ 203,656	$ 187,651	$ 171,285	$ 153,349	$ 148,618	$ 135,544	$ 117,027	$ 86,021	$ 715,941	$ 487,210	$ 325,537
Costs and expenses:
Operating costs									456,924	332,431	215,355
Depreciation and amortization									132,832	120,811	106,186
General and administrative									67,318	52,047	37,478
Intercompany leasing									0	0
Bad debt expense (recovery)									925	493	(1,642)
Impairment of equipment									484	0	0
Total costs and expenses									658,483	505,782	357,377
Income (loss) from operations	20,297	19,324	11,918	5,919	6,864	2,536	(7,856)	(20,116)	57,458	(18,572)	(31,840)
Other (expense) income:
Equity in earnings of subsidiaries									0	0	0
Interest expense									(29,721)	(26,567)	(8,928)
Impairment of investments									0	(3,331)	0
Other									(6,904)	912	596
Total other expense									(36,625)	(28,986)	(8,332)
Income (loss) before income taxes									20,833	(47,558)	(40,172)
Income tax (expense) benefit	(5,469)	(5,250)	(1,039)	2,102	(972)	1,612	4,498	9,159	(9,656)	14,297	16,957
Net income (loss)	6,818	6,744	3,650	(6,035)	(5,992)	(2,580)	(10,142)	(14,547)	11,177	(33,261)	(23,215)
Parent [Member]
Revenues									0	0	0
Costs and expenses:
Operating costs									0	0	0
Depreciation and amortization									847	1,271	1,215
General and administrative									19,797	15,337	12,222
Intercompany leasing									0	0
Bad debt expense (recovery)									0	0	0
Impairment of equipment									0
Total costs and expenses									20,644	16,608	13,437
Income (loss) from operations									(20,644)	(16,608)	(13,437)
Other (expense) income:
Equity in earnings of subsidiaries									43,182	(1,982)	(2,250)
Interest expense									(29,497)	(26,240)	(8,584)
Impairment of investments										(3,331)
Other									311	0	1,056
Total other expense									13,996	(31,553)	(9,778)
Income (loss) before income taxes									(6,648)	(48,161)	(23,215)
Income tax (expense) benefit									17,825	14,900	0
Net income (loss)									11,177	(33,261)	(23,215)
Guarantor Subsidiaries [Member]
Revenues									606,402	400,778	268,920
Costs and expenses:
Operating costs									372,945	263,649	174,579
Depreciation and amortization									119,520	109,971	97,015
General and administrative									45,152	34,177	25,293
Intercompany leasing									(4,860)	(4,323)
Bad debt expense (recovery)									925	493	(1,642)
Impairment of equipment									484
Total costs and expenses									534,166	403,967	295,245
Income (loss) from operations									72,236	(3,189)	(26,325)
Other (expense) income:
Equity in earnings of subsidiaries									(2,982)	1,335	9,245
Interest expense									(248)	(333)	(444)
Impairment of investments										0
Other									1,163	953	1,362
Total other expense									(2,067)	1,955	10,163
Income (loss) before income taxes									70,169	(1,234)	(16,162)
Income tax (expense) benefit									(26,987)	(748)	13,912
Net income (loss)									43,182	(1,982)	(2,250)
Non-Guarantor Subsidiaries [Member]
Revenues									109,539	86,432	56,617
Costs and expenses:
Operating costs									83,979	68,782	41,091
Depreciation and amortization									12,465	9,569	7,956
General and administrative									2,921	2,959	1,379
Intercompany leasing									4,857	4,323
Bad debt expense (recovery)									0	0	0
Impairment of equipment									0
Total costs and expenses									104,222	85,633	50,426
Income (loss) from operations									5,317	799	6,191
Other (expense) income:
Equity in earnings of subsidiaries									0	0	0
Interest expense									24	6	100
Impairment of investments										0
Other									(7,829)	385	(91)
Total other expense									(7,805)	391	9
Income (loss) before income taxes									(2,488)	1,190	6,200
Income tax (expense) benefit									(494)	145	3,045
Net income (loss)									(2,982)	1,335	9,245
Eliminations [Member]
Revenues									0	0	0
Costs and expenses:
Operating costs									0	0	(315)
Depreciation and amortization									0	0	0
General and administrative									(552)	(426)	(1,416)
Intercompany leasing									3	0
Bad debt expense (recovery)									0	0	0
Impairment of equipment									0
Total costs and expenses									(549)	(426)	(1,731)
Income (loss) from operations									549	426	1,731
Other (expense) income:
Equity in earnings of subsidiaries									(40,200)	647	(6,995)
Interest expense									0	0	0
Impairment of investments										0
Other									(549)	(426)	(1,731)
Total other expense									(40,749)	221	(8,726)
Income (loss) before income taxes									(40,200)	647	(6,995)
Income tax (expense) benefit									0	0	0
Net income (loss)									$ (40,200)	$ 647	$ (6,995)