Guarantor/Non Guarantor Condensed Consolidated Financial Statements (Balance Sheet (Unaudited)) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 9,703	$ 14,160	$ 35,679	$ 34,924
Receivables, net of allowance	62,212	79,816
Intercompany receivable (payable)	0	0
Inventory	8,254	9,262
Assets held for sale	6,243	4,619
Prepaid expenses and other current assets	4,730	7,411
Total current assets	91,142	115,268
Net property and equipment	629,164	702,585
Investments in subsidiaries	0	0
Intangible assets, net of accumulated amortization	781	1,944
Other long-term assets	1,710	2,196
Total assets	722,797	821,993
Current liabilities:
Accounts payable	13,014	16,951
Deferred revenues	1,157	6,222
Accrued expenses	40,838	46,869
Total current liabilities	55,009	70,042
Long-term debt, less debt issuance costs	399,508	387,217
Deferred income taxes	13,439	17,520
Other long-term liabilities	3,737	4,571
Total liabilities	471,693	479,350
Total shareholders' equity	251,104	342,643
Total liabilities and shareholders' equity	722,797	821,993
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0
Receivables, net of allowance	0	0
Intercompany receivable (payable)	0	0
Inventory	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	0	0
Total current assets	0	0
Net property and equipment	0	0
Investments in subsidiaries	(610,228)	(699,330)
Intangible assets, net of accumulated amortization	0	0
Other long-term assets	(86,830)	(84,989)
Total assets	(697,058)	(784,319)
Current liabilities:
Accounts payable	0	0
Deferred revenues	0	0
Accrued expenses	0	0
Total current liabilities	0	0
Long-term debt, less debt issuance costs	0	0
Deferred income taxes	(86,830)	(84,989)
Other long-term liabilities	0	0
Total liabilities	(86,830)	(84,989)
Total shareholders' equity	(610,228)	(699,330)
Total liabilities and shareholders' equity	(697,058)	(784,319)
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	(1,022)	(5,612)	1,770	(5,516)
Receivables, net of allowance	59,404	67,174
Intercompany receivable (payable)	31,627	31,108
Inventory	4,749	5,591
Assets held for sale	6,243	4,619
Prepaid expenses and other current assets	2,177	4,767
Total current assets	103,178	107,647
Net property and equipment	599,473	667,321
Investments in subsidiaries	28,362	42,240
Intangible assets, net of accumulated amortization	781	1,944
Other long-term assets	704	962
Total assets	732,498	820,114
Current liabilities:
Accounts payable	12,201	14,628
Deferred revenues	706	5,570
Accrued expenses	35,297	37,023
Total current liabilities	48,204	57,221
Long-term debt, less debt issuance costs	0	0
Deferred income taxes	100,269	102,509
Other long-term liabilities	2,159	3,294
Total liabilities	150,632	163,024
Total shareholders' equity	581,866	657,090
Total liabilities and shareholders' equity	732,498	820,114
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	2,626	2,551	7,560	12,752
Receivables, net of allowance	2,448	12,568
Intercompany receivable (payable)	(6,791)	(6,272)
Inventory	3,505	3,671
Assets held for sale	0	0
Prepaid expenses and other current assets	1,308	1,444
Total current assets	3,096	13,962
Net property and equipment	26,991	31,953
Investments in subsidiaries	0	0
Intangible assets, net of accumulated amortization	0	0
Other long-term assets	489	722
Total assets	30,576	46,637
Current liabilities:
Accounts payable	434	1,707
Deferred revenues	451	652
Accrued expenses	1,134	1,473
Total current liabilities	2,019	3,832
Long-term debt, less debt issuance costs	0	0
Deferred income taxes	0	0
Other long-term liabilities	195	565
Total liabilities	2,214	4,397
Total shareholders' equity	28,362	42,240
Total liabilities and shareholders' equity	30,576	46,637
Parent [Member]
Current assets:
Cash and cash equivalents	8,099	17,221	$ 26,349	$ 27,688
Receivables, net of allowance	360	74
Intercompany receivable (payable)	(24,836)	(24,836)
Inventory	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	1,245	1,200
Total current assets	(15,132)	(6,341)
Net property and equipment	2,700	3,311
Investments in subsidiaries	581,866	657,090
Intangible assets, net of accumulated amortization	0	0
Other long-term assets	87,347	85,501
Total assets	656,781	739,561
Current liabilities:
Accounts payable	379	616
Deferred revenues	0	0
Accrued expenses	4,407	8,373
Total current liabilities	4,786	8,989
Long-term debt, less debt issuance costs	399,508	387,217
Deferred income taxes	0	0
Other long-term liabilities	1,383	712
Total liabilities	405,677	396,918
Total shareholders' equity	251,104	342,643
Total liabilities and shareholders' equity	$ 656,781	$ 739,561