Supplemental Guarantors Consolidating Condensed Financial Information (Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions
REVENUE	$ 24,013	$ 23,255	$ 68,308	$ 59,545
EXPENSES:
Depreciation and amortization	17,714	18,933	61,946	58,839
Cost of sales	31	22	74	55
Selling, general and administrative	5,049	5,386	15,700	16,013
Total operating expenses	22,794	24,341	77,720	74,907
INCOME (LOSS) FROM OPERATIONS	1,219	(1,086)	(9,412)	(15,362)
Interest income (expense), net	(6,139)	(6,298)	(18,536)	(18,988)
Foreign currency exchange gains (losses)	(3)	(20)	(88)	143
Other income	0	572	96	582
Income (loss) before income taxes and equity in income (loss) of subsidiaries	(4,923)	(6,832)	(27,940)	(33,625)
Provision (benefit) for income taxes	1,421	(1,389)	1,419	(5,083)
Equity in income (loss) of subsidiaries	0	0	0	0
NET LOSS	(6,344)	(5,443)	(29,359)	(28,542)
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions
REVENUE	(540)	(319)	(1,482)	(1,031)
EXPENSES:
Depreciation and amortization	0	(13)	(25)	(38)
Cost of sales	(214)	2	(504)	(54)
Selling, general and administrative	(326)	(321)	(978)	(977)
Total operating expenses	(540)	(332)	(1,507)	(1,069)
INCOME (LOSS) FROM OPERATIONS	0	13	25	38
Interest income (expense), net	0	0	0	0
Foreign currency exchange gains (losses)	0	0	0	0
Other income		0	0	0
Income (loss) before income taxes and equity in income (loss) of subsidiaries	0	13	25	38
Provision (benefit) for income taxes	0	0	0	0
Equity in income (loss) of subsidiaries	(4,904)	(14)	5,989	13,853
NET LOSS	(4,904)	(1)	6,014	13,891
Parent [Member]
Condensed Financial Statements, Captions
REVENUE	0	0	0	0
EXPENSES:
Depreciation and amortization	0	0	0	0
Cost of sales	0	0	0	0
Selling, general and administrative	169	315	429	888
Total operating expenses	169	315	429	888
INCOME (LOSS) FROM OPERATIONS	(169)	(315)	(429)	(888)
Interest income (expense), net	(6,046)	(5,732)	(17,959)	(17,034)
Foreign currency exchange gains (losses)	0	0	0	0
Other income		0	0	0
Income (loss) before income taxes and equity in income (loss) of subsidiaries	(6,215)	(6,047)	(18,388)	(17,922)
Provision (benefit) for income taxes	0	0	0	0
Equity in income (loss) of subsidiaries	(129)	604	(10,971)	(10,620)
NET LOSS	(6,344)	(5,443)	(29,359)	(28,542)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions
REVENUE	13,148	20,017	46,241	49,297
EXPENSES:
Depreciation and amortization	14,011	15,071	48,493	44,237
Cost of sales	244	19	571	96
Selling, general and administrative	3,916	3,799	12,553	11,256
Total operating expenses	18,171	18,889	61,617	55,589
INCOME (LOSS) FROM OPERATIONS	(5,023)	1,128	(15,376)	(6,292)
Interest income (expense), net	(142)	(497)	(608)	(1,703)
Foreign currency exchange gains (losses)	(2)	0	0	0
Other income		572	0	581
Income (loss) before income taxes and equity in income (loss) of subsidiaries	(5,167)	1,203	(15,984)	(7,414)
Provision (benefit) for income taxes	(5)	22	(6)	11
Equity in income (loss) of subsidiaries	5,033	(590)	4,982	(3,233)
NET LOSS	(129)	591	(10,996)	(10,658)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions
REVENUE	11,405	3,557	23,549	11,279
EXPENSES:
Depreciation and amortization	3,703	3,875	13,478	14,640
Cost of sales	1	1	7	13
Selling, general and administrative	1,290	1,593	3,696	4,846
Total operating expenses	4,994	5,469	17,181	19,499
INCOME (LOSS) FROM OPERATIONS	6,411	(1,912)	6,368	(8,220)
Interest income (expense), net	49	(69)	31	(251)
Foreign currency exchange gains (losses)	(1)	(20)	(88)	143
Other income		0	96	1
Income (loss) before income taxes and equity in income (loss) of subsidiaries	6,459	(2,001)	6,407	(8,327)
Provision (benefit) for income taxes	1,426	(1,411)	1,425	(5,094)
Equity in income (loss) of subsidiaries	0	0	0	0
NET LOSS	$ 5,033	$ (590)	$ 4,982	$ (3,233)