Fair Value Measurements (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Capitalized mortgage servicing rights
Moving average term of U.S. Treasury rate used to estimate the discount rate in order to determine the fair value of servicing rights	10 years
Percentage added to the moving average 10-year U.S. Treasury rate to estimate the discount rate used to determine the fair value of servicing rights	5.00%
Short-term FHLB borrowings
Maturity period of short-term FHLB borrowings	90 days
Non-recurring basis
Fair value measurements
Adjustments to Fair Value	$ (259)	$ (339)
Non-recurring basis \| Impaired Loans
Fair value measurements
Adjustments to Fair Value	(240)	(320)
Non-recurring basis \| Other Real Estate Owned
Fair value measurements
Adjustments to Fair Value	(19)	(19)
Non-recurring basis \| Level 3
Fair value measurements
Assets at Fair Value	2,732	2,966
Non-recurring basis \| Level 3 \| Impaired Loans
Fair value measurements
Assets at Fair Value	2,463	2,763
Non-recurring basis \| Level 3 \| Other Real Estate Owned
Fair value measurements
Assets at Fair Value	269	203
Non-recurring basis \| Assets at Fair Value
Fair value measurements
Assets at Fair Value	2,732	2,966
Non-recurring basis \| Assets at Fair Value \| Impaired Loans
Fair value measurements
Assets at Fair Value	2,463	2,763
Non-recurring basis \| Assets at Fair Value \| Other Real Estate Owned
Fair value measurements
Assets at Fair Value	$ 269	$ 203

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- Definition

Moving average term of U.S. Treasury rate used to estimate the discount rate in order to determine the fair value of servicing rights.

+ References

No definition available.

+ Details

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- Definition

Represents the percentage added to the reference rate to reflect the current credit spreads and conditions in the market to estimate the discount rate used to determine the fair value of servicing assets.

+ References

No definition available.

+ Details

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- Definition

Represents the maturity period of short-term advances from the Federal Home Loan Bank.

+ References

No definition available.

+ Details

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- Definition

The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 45, 46, 47

-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 Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

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- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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