Debt Schedule of Unamortized Prepaid Debt Fees (Details) (USD $) In Thousands	Aug. 05, 2011 2011 Senior Secured Credit Facility [Member]	Sep. 30, 2011 2011 Senior Secured Credit Facility [Member] Credit Facilities [Member]	Dec. 31, 2010 2007 Senior Secured Credit Facility [Member] Credit Facilities [Member]
Debt Instrument [Line Items]
Prepaid Debt Fees Noncurrent	$ 6,200	$ 5,963	$ 4,483