Supplemental Guarantors Consolidating Condensed Financial Information - (Statement of Operations) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
REVENUE	$ 21,942,000	$ 24,013,000	$ 23,700,000	$ 20,595,000	$ 35,001,000	$ 23,255,000	$ 24,340,000	$ 11,950,000	$ 90,250,000	$ 94,546,000	$ 100,252,000
EXPENSES:
Depreciation and amortization									77,482,000	75,078,000	80,923,000
Cost of sales									96,000	76,000	195,000
Selling, general and administrative									20,291,000	24,119,000	22,184,000
Total operating expenses									97,869,000	99,273,000	103,302,000
INCOME (LOSS) FROM OPERATIONS	1,793,000	1,219,000	(3,307,000)	(7,324,000)	10,635,000	(1,086,000)	(5,144,000)	(9,132,000)	(7,619,000)	(4,727,000)	(3,050,000)
Interest expense, net									(24,652,000)	(24,967,000)	(25,390,000)
Foreign currency exchange gains (losses)									8,000	109,000	(1,650,000)
Other income									97,000	1,765,000	5,000
Loss before income taxes									(32,166,000)	(27,820,000)	(30,085,000)
Provision (benefit) for income taxes									(685,000)	(3,396,000)	79,905,000
Equity in income (loss) of subsidiaries									0	0	0
NET LOSS	$ (2,122,000)	$ (6,344,000)	$ (9,636,000)	$ (13,379,000)	$ 4,118,000	$ (5,443,000)	$ (9,235,000)	$ (13,864,000)	(31,481,000)	(24,424,000)	(109,990,000)
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									(1,837,000)	(1,382,000)	(1,319,000)
EXPENSES:
Depreciation and amortization									(25,000)	(50,000)	(49,000)
Cost of sales									(549,000)	(50,000)	0
Selling, general and administrative									(1,288,000)	(1,332,000)	(1,319,000)
Total operating expenses									(1,862,000)	(1,432,000)	(1,368,000)
INCOME (LOSS) FROM OPERATIONS									25,000	50,000	49,000
Interest expense, net									0	0	0
Foreign currency exchange gains (losses)									0	0	0
Other income									0	0	0
Loss before income taxes									25,000	50,000	49,000
Provision (benefit) for income taxes									0	0	0
Equity in income (loss) of subsidiaries									3,609,000	(546,000)	84,713,000
NET LOSS									3,634,000	(496,000)	84,762,000
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									0	0	0
EXPENSES:
Depreciation and amortization									0	0	0
Cost of sales									0	0	0
Selling, general and administrative									595,000	1,078,000	1,016,000
Total operating expenses									595,000	1,078,000	1,016,000
INCOME (LOSS) FROM OPERATIONS									(595,000)	(1,078,000)	(1,016,000)
Interest expense, net									(24,166,000)	(22,910,000)	(22,845,000)
Foreign currency exchange gains (losses)									0	0	0
Other income									0	0	0
Loss before income taxes									(24,761,000)	(23,988,000)	(23,861,000)
Provision (benefit) for income taxes									(2,357,000)	0	9,270,000
Equity in income (loss) of subsidiaries									(9,077,000)	(436,000)	(76,859,000)
NET LOSS									(31,481,000)	(24,424,000)	(109,990,000)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									62,231,000	73,667,000	72,593,000
EXPENSES:
Depreciation and amortization									59,263,000	55,934,000	51,455,000
Cost of sales									639,000	112,000	123,000
Selling, general and administrative									16,232,000	17,590,000	15,362,000
Total operating expenses									76,134,000	73,636,000	66,940,000
INCOME (LOSS) FROM OPERATIONS									(13,903,000)	31,000	5,653,000
Interest expense, net									(599,000)	(2,043,000)	(2,146,000)
Foreign currency exchange gains (losses)									(1,000)	0	(3,000)
Other income									0	587,000	5,000
Loss before income taxes									(14,503,000)	(1,425,000)	3,509,000
Provision (benefit) for income taxes									67,000	43,000	72,563,000
Equity in income (loss) of subsidiaries									5,468,000	982,000	(7,854,000)
NET LOSS									(9,102,000)	(486,000)	(76,908,000)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									29,856,000	22,261,000	28,978,000
EXPENSES:
Depreciation and amortization									18,244,000	19,194,000	29,517,000
Cost of sales									6,000	14,000	72,000
Selling, general and administrative									4,752,000	6,783,000	7,125,000
Total operating expenses									23,002,000	25,991,000	36,714,000
INCOME (LOSS) FROM OPERATIONS									6,854,000	(3,730,000)	(7,736,000)
Interest expense, net									113,000	(14,000)	(399,000)
Foreign currency exchange gains (losses)									9,000	109,000	(1,647,000)
Other income									97,000	1,178,000	0
Loss before income taxes									7,073,000	(2,457,000)	(9,782,000)
Provision (benefit) for income taxes									1,605,000	(3,439,000)	(1,928,000)
Equity in income (loss) of subsidiaries									0	0	0
NET LOSS									$ 5,468,000	$ 982,000	$ (7,854,000)