Fair Value Measurement (Details 5) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans Held-for-sale, Fair Value Disclosure	$ 30,077	$ 41,340
Fair Value, Option, Loans Held as Assets, Aggregate Difference	1,129	316
Aggregate Fair Value [Member]
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans Held-for-sale, Fair Value Disclosure	30,077	41,340
Contractual Balance [Member]
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans Held-for-sale, Fair Value Disclosure	$ 28,948	$ 41,024

For loans held as assets for which the fair value option has been elected, this item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of those loans that are 90 days or more past due, in nonaccrual status, or both.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph e(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 28

-Subparagraph (e)(3)

-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

Name:	us-gaap_FairValueOptionLoansHeldAsAssetsAggregateDifference
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant