Noncovered Loans (Narrative) (Details) (USD $)	9 Months Ended
Sep. 30, 2012 contract	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Loans to related parties	$ 13,500,000	$ 9,000,000
Advances on related party loans	6,900,000
Repayments on related party loans	2,400,000
Additional funds committed to lend on loans classified as TDR	1,200,000	535,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0
Loans Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	441,600,000	462,000,000
Federal Reserve Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	$ 61,700,000	$ 351,300,000

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Paragraph 17

-IssueDate 2006-05-01

-Chapter 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 860

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7523297&loc=d3e113969-111729

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 01-6

-Paragraph 14

-Subparagraph f, h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 17

-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 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

- Definition

For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

+ References+ Details

- Definition

Reflects the amount of new advances made to related parties in the form of loan and lease receivables.

+ References+ Details

- Definition

Reflects the amount of collections received from related parties to reduce the carrying amounts of loans and leases receivable due from them.

+ References+ Details