Supplemental Guarantors Consolidating Condensed Financial Information - (Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
REVENUE	$ 13,962	$ 31,242	$ 30,722	$ 24,326	$ 52,351	$ 41,299	$ 47,334	$ 57,053	$ 100,252	$ 198,037	$ 202,874
EXPENSES:
Depreciation and amortization									80,923	121,023	121,598
Cost of sales									195	304	475
Selling, general and administrative									22,184	29,799	25,971
Total operating expenses									103,302	151,126	148,044
INCOME (LOSS) FROM OPERATIONS	(3,912)	1,285	4,745	(5,168)	8,944	15,780	10,543	11,644	(3,050)	46,911	54,830
Interest expense, net									(25,390)	(25,029)	(27,851)
Foreign currency exchange gains (losses)									(1,650)	(1,974)	(2,222)
Loss on early extinguishment of debt									0	0	(1,504)
Other income									5	63	488
Income (loss) before income taxes									(30,085)	19,971	23,741
Provision (benefit) for income taxes									79,905	10,293	(89,940)
Equity in income of subsidiaries									0	0	0
NET INCOME (LOSS)	$ (96,013)	$ (4,055)	$ (2,276)	$ (7,646)	$ 725	$ 4,486	$ 2,575	$ 1,892	(109,990)	9,678	113,681
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									1,016	2,130	1,587
Total operating expenses									1,016	2,130	1,587
INCOME (LOSS) FROM OPERATIONS									(1,016)	(2,130)	(1,587)
Interest expense, net									(22,845)	(21,407)	(23,194)
Foreign currency exchange gains (losses)									0	0	0
Loss on early extinguishment of debt											(1,504)
Other income									0	(14)	0
Income (loss) before income taxes									(23,861)	(23,551)	(26,285)
Provision (benefit) for income taxes									9,270	(9,270)	0
Equity in income of subsidiaries									(76,859)	23,959	139,966
NET INCOME (LOSS)									(109,990)	9,678	113,681
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									72,593	153,125	154,686
EXPENSES:
Depreciation and amortization									51,455	80,835	86,426
Cost of sales									123	284	471
Selling, general and administrative									15,362	19,304	16,701
Total operating expenses									66,940	100,423	103,598
INCOME (LOSS) FROM OPERATIONS									5,653	52,702	51,088
Interest expense, net									(2,146)	(2,360)	(2,945)
Foreign currency exchange gains (losses)									(3)	3	0
Loss on early extinguishment of debt											0
Other income									5	71	737
Income (loss) before income taxes									3,509	50,416	48,880
Provision (benefit) for income taxes									72,563	21,063	(90,320)
Equity in income of subsidiaries									(7,854)	(5,452)	984
NET INCOME (LOSS)									(76,908)	23,901	140,184
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									28,978	46,287	49,488
EXPENSES:
Depreciation and amortization									29,517	40,246	35,203
Cost of sales									72	20	4
Selling, general and administrative									7,125	9,740	8,983
Total operating expenses									36,714	50,006	44,190
INCOME (LOSS) FROM OPERATIONS									(7,736)	(3,719)	5,298
Interest expense, net									(399)	(1,262)	(1,712)
Foreign currency exchange gains (losses)									(1,647)	(1,977)	(2,222)
Loss on early extinguishment of debt											0
Other income									0	6	0
Income (loss) before income taxes									(9,782)	(6,952)	1,364
Provision (benefit) for income taxes									(1,928)	(1,500)	380
Equity in income of subsidiaries									0	0	0
NET INCOME (LOSS)									(7,854)	(5,452)	984
Consolidating Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE									(1,319)	(1,375)	(1,300)
EXPENSES:
Depreciation and amortization									(49)	(58)	(31)
Cost of sales									0	0	0
Selling, general and administrative									(1,319)	(1,375)	(1,300)
Total operating expenses									(1,368)	(1,433)	(1,331)
INCOME (LOSS) FROM OPERATIONS									49	58	31
Interest expense, net									0	0	0
Foreign currency exchange gains (losses)									0	0	0
Loss on early extinguishment of debt											0
Other income									0	0	(249)
Income (loss) before income taxes									49	58	(218)
Provision (benefit) for income taxes									0	0	0
Equity in income of subsidiaries									84,713	(18,507)	(140,950)
NET INCOME (LOSS)									$ 84,762	$ (18,449)	$ (141,168)