Fair Value Measurements, Quantative information (Details) (Impaired Loans [Member], Discounted Appraised Value [Member], Level III [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013
Fair Value, Option, Quantitative Disclosures [Line Items]
Level III financial assets fair value	1,900
Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unobservable inputs value assumptions percentage (in hundredths)	10.00%
Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unobservable inputs value assumptions percentage (in hundredths)	30.00%
Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unobservable inputs value assumptions percentage (in hundredths)	21.00%

Carrying amount of items included in each line item in the statement of financial position that are not eligible for the fair value option.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph c(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (c)(2)

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

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