Miscellaneous Financial Information (Unaudited), Debt Repayment (Details) (USD $) In Thousands, unless otherwise specified			1 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Jan. 31, 2011 Bank Term Loan [Member]
Short-term Debt [Line Items]
Short-term debt	$ 0	$ 150,000	$ 150,000
Maturity date			Aug. 19, 2011

Carrying amount at the balance sheet date of borrowings from a bank, not elsewhere enumerated in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph a

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 16

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(a)(1))

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

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