Borrowings (Total Obligations Under Senior Secured Notes) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Senior Secured Notes	$ 0	$ 304,645
Secured Senior Notes [Member]
Debt Instrument [Line Items]
Senior Secured Notes	950,643	932,764
Secured Senior Notes [Member] \| Senior Secured Notes Due 2016 [Member]
Debt Instrument [Line Items]
Senior Secured Notes	953,705	935,971
Unamortized debt discount	$ (3,062)	$ (3,207)

Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_SeniorLongTermNotes
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant