Guarantor/Non Guarantor Condensed Consolidated Financial Statements (Balance Sheet (Unaudited)) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 7,290	$ 10,194	$ 18,669	$ 14,160
Receivables, net of allowance	80,488	72,123
Intercompany receivable (payable)	0	0
Inventory	11,571	9,660
Assets held for sale	11,405	15,093
Prepaid expenses and other current assets	5,859	6,926
Total current assets	116,613	113,996
Net property and equipment	590,224	584,080
Investments in subsidiaries	0	0
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	0	0
Other long-term assets	1,491	2,026
Total assets	708,328	700,102	786,525
Current liabilities:
Accounts payable	22,793	19,208
Deferred revenues	581	1,449
Accrued expenses	40,123	45,345
Total current liabilities	63,497	66,002
Long-term debt, less debt issuance costs	373,633	339,473
Deferred income taxes	8,044	8,180
Other long-term liabilities	5,917	5,049
Total liabilities	451,091	418,704
Total shareholders' equity	257,237	281,398
Total liabilities and shareholders' equity	708,328	700,102
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Receivables, net of allowance	33	(513)
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	33	(513)
Net property and equipment	0	0
Investments in subsidiaries	(614,919)	(602,235)
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	(60,672)	(65,041)
Other long-term assets	0	0
Total assets	(675,558)	(667,789)
Current liabilities:
Accounts payable	0	0
Deferred revenues	0	0
Accrued expenses	33	(513)
Total current liabilities	33	(513)
Long-term debt, less debt issuance costs	0	0
Deferred income taxes	(60,672)	(65,041)
Other long-term liabilities	0	0
Total liabilities	(60,639)	(65,554)
Total shareholders' equity	(614,919)	(602,235)
Total liabilities and shareholders' equity	(675,558)	(667,789)
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	(851)	(764)	152	(5,612)
Receivables, net of allowance	64,990	64,946
Intercompany receivable (payable)	43,657	35,427
Inventory	6,358	5,659
Assets held for sale	11,347	15,035
Prepaid expenses and other current assets	3,793	4,014
Total current assets	129,294	124,317
Net property and equipment	563,362	556,062
Investments in subsidiaries	23,572	24,270
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	0	0
Other long-term assets	997	1,029
Total assets	717,225	705,678
Current liabilities:
Accounts payable	20,158	16,317
Deferred revenues	334	680
Accrued expenses	33,562	34,765
Total current liabilities	54,054	51,762
Long-term debt, less debt issuance costs	0	0
Deferred income taxes	68,716	73,249
Other long-term liabilities	3,108	2,702
Total liabilities	125,878	127,713
Total shareholders' equity	591,347	577,965
Total liabilities and shareholders' equity	717,225	705,678
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	872	1,060	2,735	2,551
Receivables, net of allowance	15,462	7,210
Intercompany receivable (payable)	(18,821)	(10,591)
Inventory	5,213	4,001
Assets held for sale	58	58
Prepaid expenses and other current assets	841	1,632
Total current assets	3,625	3,370
Net property and equipment	24,521	25,517
Investments in subsidiaries	0	0
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	0	0
Other long-term assets	33	414
Total assets	28,179	29,301
Current liabilities:
Accounts payable	2,193	2,345
Deferred revenues	247	769
Accrued expenses	2,081	1,777
Total current liabilities	4,521	4,891
Long-term debt, less debt issuance costs	0	0
Deferred income taxes	0	(28)
Other long-term liabilities	86	168
Total liabilities	4,607	5,031
Total shareholders' equity	23,572	24,270
Total liabilities and shareholders' equity	28,179	29,301
Parent [Member]
Current assets:
Cash and cash equivalents	7,269	9,898	$ 15,782	$ 17,221
Receivables, net of allowance	3	480
Intercompany receivable (payable)	(24,836)	(24,836)
Inventory	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	1,225	1,280
Total current assets	(16,339)	(13,178)
Net property and equipment	2,341	2,501
Investments in subsidiaries	591,347	577,965
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	60,672	65,041
Other long-term assets	461	583
Total assets	638,482	632,912
Current liabilities:
Accounts payable	442	546
Deferred revenues	0	0
Accrued expenses	4,447	9,316
Total current liabilities	4,889	9,862
Long-term debt, less debt issuance costs	373,633	339,473
Deferred income taxes	0	0
Other long-term liabilities	2,723	2,179
Total liabilities	381,245	351,514
Total shareholders' equity	257,237	281,398
Total liabilities and shareholders' equity	$ 638,482	$ 632,912