Supplemental Guarantors Consolidating Condensed Financial Information (Statement of Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Condensed Financial Statements, Captions [Line Items]
REVENUE	$ 51,351	$ 72,547
EXPENSES:
Depreciation and amortization	29,338	39,384
Cost of sales	39	97
Selling, general and administrative	7,387	8,092
Total operating expenses	36,764	47,573
INCOME (LOSS) FROM OPERATIONS	14,587	24,974
Interest expense, net	9,315	7,219
Foreign currency exchange gains (losses)	(647)	411
Loss on early extinguishment of debt	(1,504)	0
Other income	1	81
Income (loss) before income taxes and equity in income of subsidiaries	3,122	18,247
Provision for income taxes	1,384	3,541
Equity in Income (Loss) of Subsidiaries	0	0
NET INCOME	1,738	14,706
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE	0	0
EXPENSES:
Depreciation and amortization	0	0
Cost of sales	0	0
Selling, general and administrative	285	253
Total operating expenses	285	253
INCOME (LOSS) FROM OPERATIONS	(285)	(253)
Interest expense, net	(7,831)	(2,246)
Foreign currency exchange gains (losses)	0	0
Loss on early extinguishment of debt	(1,504)
Other income	0	1
Income (loss) before income taxes and equity in income of subsidiaries	(9,620)	(2,498)
Provision for income taxes	0	0
Equity in Income (Loss) of Subsidiaries	11,358	17,204
NET INCOME	1,738	14,706
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE	33,120	39,128
EXPENSES:
Depreciation and amortization	18,009	20,848
Cost of sales	38	86
Selling, general and administrative	4,463	5,016
Total operating expenses	22,510	25,950
INCOME (LOSS) FROM OPERATIONS	10,610	13,178
Interest expense, net	(1,065)	(4,710)
Foreign currency exchange gains (losses)	0	0
Loss on early extinguishment of debt	0
Other income	1	80
Income (loss) before income taxes and equity in income of subsidiaries	9,546	8,548
Provision for income taxes	484	260
Equity in Income (Loss) of Subsidiaries	2,296	8,916
NET INCOME	11,358	17,204
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE	18,575	33,764
EXPENSES:
Depreciation and amortization	11,329	18,536
Cost of sales	1	11
Selling, general and administrative	2,983	3,168
Total operating expenses	14,313	21,715
INCOME (LOSS) FROM OPERATIONS	4,262	12,049
Interest expense, net	(419)	(263)
Foreign currency exchange gains (losses)	(647)	411
Loss on early extinguishment of debt	0
Other income	0	0
Income (loss) before income taxes and equity in income of subsidiaries	3,196	12,197
Provision for income taxes	900	3,281
Equity in Income (Loss) of Subsidiaries	0	0
NET INCOME	2,296	8,916
Consolidating Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
REVENUE	(344)	(345)
EXPENSES:
Depreciation and amortization	0	0
Cost of sales	0	0
Selling, general and administrative	(344)	(345)
Total operating expenses	(344)	(345)
INCOME (LOSS) FROM OPERATIONS	0	0
Interest expense, net	0	0
Foreign currency exchange gains (losses)	0	0
Loss on early extinguishment of debt	0
Other income	0	0
Income (loss) before income taxes and equity in income of subsidiaries	0	0
Provision for income taxes	0	0
Equity in Income (Loss) of Subsidiaries	(13,654)	(26,120)
NET INCOME	$ (13,654)	$ (26,120)