Guarantor/Non-Guarantor Condensed Consolidated Financial Statements (Balance Sheet (Unaudited)) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 20,810	$ 27,385	$ 10,508	$ 23,733
Restricted Cash	210,401	0
Receivables, net of allowance	182,732	176,360
Intercompany receivable (payable)	0	0
Deferred income taxes	11,569	13,092
Inventory	13,750	13,232
Prepaid expenses and other current assets	6,610	9,311
Total current assets	445,872	239,380
Net property and equipment	926,929	937,657
Investments in subsidiaries	0	0
Intangible assets, net of accumulated amortization	30,272	32,269
Noncurrent deferred income taxes	4,020	1,156
Other long-term assets	19,284	19,161
Total assets	1,426,377	1,229,623	1,324,257
Current liabilities:
Accounts payable	53,969	43,718
Current portion of long-term debt	202,166	2,847
Deferred revenues	2,159	699
Accrued expenses	58,094	73,569
Total current liabilities	316,388	120,833
Long-term debt, less current portion	501,133	499,666
Noncurrent deferred income taxes	84,596	84,636
Other long-term liabilities	6,706	6,055
Total liabilities	908,823	711,190
Total shareholders' equity	517,554	518,433
Total liabilities and shareholders' equity	1,426,377	1,229,623
Parent [Member]
Current assets:
Cash and cash equivalents	10,554	28,368	9,343	18,479
Restricted Cash	210,401
Receivables, net of allowance	881	905
Intercompany receivable (payable)	(24,837)	(24,837)
Deferred income taxes	3,323	1,143
Inventory	0	0
Prepaid expenses and other current assets	816	1,013
Total current assets	201,138	6,592
Net property and equipment	4,580	4,531
Investments in subsidiaries	923,552	939,091
Intangible assets, net of accumulated amortization	75	75
Noncurrent deferred income taxes	85,295	78,486
Other long-term assets	11,983	7,513
Total assets	1,226,623	1,036,288
Current liabilities:
Accounts payable	1,198	757
Current portion of long-term debt	200,528	0
Deferred revenues	0	0
Accrued expenses	4,953	16,368
Total current liabilities	206,679	17,125
Long-term debt, less current portion	501,060	499,586
Noncurrent deferred income taxes	0	0
Other long-term liabilities	580	394
Total liabilities	708,319	517,105
Total shareholders' equity	518,304	519,183
Total liabilities and shareholders' equity	1,226,623	1,036,288
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	(4,237)	(2,059)	(3,127)	(5,401)
Restricted Cash	0
Receivables, net of allowance	143,967	125,979
Intercompany receivable (payable)	52,889	52,671
Deferred income taxes	7,008	8,005
Inventory	8,016	7,415
Prepaid expenses and other current assets	4,923	7,094
Total current assets	212,566	199,105
Net property and equipment	832,094	846,632
Investments in subsidiaries	121,187	120,630
Intangible assets, net of accumulated amortization	30,197	32,194
Noncurrent deferred income taxes	0	0
Other long-term assets	1,853	2,009
Total assets	1,197,897	1,200,570
Current liabilities:
Accounts payable	47,517	37,797
Current portion of long-term debt	1,638	2,847
Deferred revenues	2,159	699
Accrued expenses	47,269	51,739
Total current liabilities	98,583	93,082
Long-term debt, less current portion	73	80
Noncurrent deferred income taxes	169,891	163,122
Other long-term liabilities	5,798	5,195
Total liabilities	274,345	261,479
Total shareholders' equity	923,552	939,091
Total liabilities and shareholders' equity	1,197,897	1,200,570
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	14,493	1,076	4,292	10,655
Restricted Cash	0
Receivables, net of allowance	40,070	49,476
Intercompany receivable (payable)	(28,052)	(27,834)
Deferred income taxes	1,238	3,944
Inventory	5,734	5,817
Prepaid expenses and other current assets	871	1,204
Total current assets	34,354	33,683
Net property and equipment	91,005	87,244
Investments in subsidiaries	0	0
Intangible assets, net of accumulated amortization	0	0
Noncurrent deferred income taxes	4,020	1,156
Other long-term assets	5,448	9,639
Total assets	134,827	131,722
Current liabilities:
Accounts payable	5,254	5,164
Current portion of long-term debt	0	0
Deferred revenues	0	0
Accrued expenses	8,058	5,462
Total current liabilities	13,312	10,626
Long-term debt, less current portion	0	0
Noncurrent deferred income taxes	0	0
Other long-term liabilities	328	466
Total liabilities	13,640	11,092
Total shareholders' equity	121,187	120,630
Total liabilities and shareholders' equity	134,827	131,722
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0
Restricted Cash	0
Receivables, net of allowance	(2,186)	0
Intercompany receivable (payable)	0	0
Deferred income taxes	0	0
Inventory	0	0
Prepaid expenses and other current assets	0	0
Total current assets	(2,186)	0
Net property and equipment	(750)	(750)
Investments in subsidiaries	(1,044,739)	(1,059,721)
Intangible assets, net of accumulated amortization	0	0
Noncurrent deferred income taxes	(85,295)	(78,486)
Other long-term assets	0	0
Total assets	(1,132,970)	(1,138,957)
Current liabilities:
Accounts payable	0	0
Current portion of long-term debt	0	0
Deferred revenues	0	0
Accrued expenses	(2,186)	0
Total current liabilities	(2,186)	0
Long-term debt, less current portion	0	0
Noncurrent deferred income taxes	(85,295)	(78,486)
Other long-term liabilities	0	0
Total liabilities	(87,481)	(78,486)
Total shareholders' equity	(1,045,489)	(1,060,471)
Total liabilities and shareholders' equity	$ (1,132,970)	$ (1,138,957)