Guarantor/Non-Guarantor Condensed Consolidated Financial Statements (Balance Sheet (Unaudited)) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 27,385		$ 23,733	$ 86,197	$ 22,011
Receivables, net of allowance	176,360		158,844
Intercompany receivable (payable)	0		0
Deferred income taxes	13,092		11,058
Inventory	13,232		12,111
Prepaid expenses and other current assets	9,311		13,040
Total current assets	239,380		218,786
Net property and equipment	937,657		1,014,340
Investments in subsidiaries	0		0
Intangible assets	32,269		43,843
Goodwill	0	0	41,683	41,700
Noncurrent deferred income taxes	1,156		5,519
Other long-term assets	19,161		15,605
Total assets	1,229,623		1,339,776	1,172,754
Current liabilities:
Accounts payable	43,718		83,823
Current portion of long-term debt	2,847		872
Deferred revenues	699		3,880
Accrued expenses	73,569		67,975
Total current liabilities	120,833		156,550
Long-term debt, less current portion	499,666		518,725
Noncurrent deferred income taxes	84,636		108,838
Other long-term liabilities	6,055		7,983
Total liabilities	711,190		792,096
Total shareholders' equity	518,433		547,680	510,445	396,333
Total liabilities and shareholders' equity	1,229,623		1,339,776
Parent [Member]
Current assets:
Cash and cash equivalents	28,368		18,479	91,932	15,737
Receivables, net of allowance	905		440
Intercompany receivable (payable)	(24,837)		(124,516)
Deferred income taxes	1,143		869
Inventory	0		0
Prepaid expenses and other current assets	1,013		655
Total current assets	6,592		(104,073)
Net property and equipment	4,531		3,474
Investments in subsidiaries	939,091		1,122,814
Intangible assets	75		68
Goodwill			0
Noncurrent deferred income taxes	78,486		51,834
Other long-term assets	7,513		9,582
Total assets	1,036,288		1,083,699
Current liabilities:
Accounts payable	757		1,558
Current portion of long-term debt	0		0
Deferred revenues	0		0
Accrued expenses	16,368		14,905
Total current liabilities	17,125		16,463
Long-term debt, less current portion	499,586		518,618
Noncurrent deferred income taxes	0		(4)
Other long-term liabilities	394		192
Total liabilities	517,105		535,269
Total shareholders' equity	519,183		548,430
Total liabilities and shareholders' equity	1,036,288		1,083,699
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	(2,059)		(5,401)	(13,879)	(1,840)
Receivables, net of allowance	125,979		129,570
Intercompany receivable (payable)	52,671		146,652
Deferred income taxes	8,005		8,162
Inventory	7,415		5,956
Prepaid expenses and other current assets	7,094		9,163
Total current assets	199,105		294,102
Net property and equipment	846,632		921,393
Investments in subsidiaries	120,630		114,416
Intangible assets	32,194		43,775
Goodwill			41,683
Noncurrent deferred income taxes	0		0
Other long-term assets	2,009		2,340
Total assets	1,200,570		1,417,709
Current liabilities:
Accounts payable	37,797		76,828
Current portion of long-term debt	2,847		872
Deferred revenues	699		1,954
Accrued expenses	51,739		48,892
Total current liabilities	93,082		128,546
Long-term debt, less current portion	80		107
Noncurrent deferred income taxes	163,122		160,676
Other long-term liabilities	5,195		5,566
Total liabilities	261,479		294,895
Total shareholders' equity	939,091		1,122,814
Total liabilities and shareholders' equity	1,200,570		1,417,709
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	1,076		10,655	8,144	8,114
Receivables, net of allowance	49,476		29,128
Intercompany receivable (payable)	(27,834)		(22,136)
Deferred income taxes	3,944		2,027
Inventory	5,817		6,155
Prepaid expenses and other current assets	1,204		3,222
Total current assets	33,683		29,051
Net property and equipment	87,244		90,223
Investments in subsidiaries	0		0
Intangible assets	0		0
Goodwill			0
Noncurrent deferred income taxes	1,156		5,519
Other long-term assets	9,639		3,683
Total assets	131,722		128,476
Current liabilities:
Accounts payable	5,164		5,437
Current portion of long-term debt	0		0
Deferred revenues	0		1,926
Accrued expenses	5,462		4,472
Total current liabilities	10,626		11,835
Long-term debt, less current portion	0		0
Noncurrent deferred income taxes	0		0
Other long-term liabilities	466		2,225
Total liabilities	11,092		14,060
Total shareholders' equity	120,630		114,416
Total liabilities and shareholders' equity	131,722		128,476
Eliminations [Member]
Current assets:
Cash and cash equivalents	0		0
Receivables, net of allowance	0		(294)
Intercompany receivable (payable)	0		0
Deferred income taxes	0		0
Inventory	0		0
Prepaid expenses and other current assets	0		0
Total current assets	0		(294)
Net property and equipment	(750)		(750)
Investments in subsidiaries	(1,059,721)		(1,237,230)
Intangible assets	0		0
Goodwill			0
Noncurrent deferred income taxes	(78,486)		(51,834)
Other long-term assets	0		0
Total assets	(1,138,957)		(1,290,108)
Current liabilities:
Accounts payable	0		0
Current portion of long-term debt	0		0
Deferred revenues	0		0
Accrued expenses	0		(294)
Total current liabilities	0		(294)
Long-term debt, less current portion	0		0
Noncurrent deferred income taxes	(78,486)		(51,834)
Other long-term liabilities	0		0
Total liabilities	(78,486)		(52,128)
Total shareholders' equity	(1,060,471)		(1,237,980)
Total liabilities and shareholders' equity	$ (1,138,957)		$ (1,290,108)