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Commitments and Off-Balance Sheet Risk (Details) (USD $) | Dec. 31, 2012 | Dec. 31, 2011
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Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | $ 334,768,000 | $ 254,130,000
Commercial unused lines of credit [Member] |  |
Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | 222,237,000 | 171,683,000
Unused lines of credit secured by 1 - 4 family residential properties [Member] |  |
Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | 24,250,000 | 24,663,000
Credit card unused lines of credit [Member] |  |
Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | 8,512,000 | 7,565,000
Other consumer unused lines of credit [Member] |  |
Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | 4,613,000 | 3,367,000
Loan Commitments [Member] |  |
Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | 64,565,000 | 30,929,000
Standby letters of credit [Member] |  |
Summary of contractual amounts of financial instruments with off-balance sheet risk |  |
Contractual amounts of financial instruments with off-balance sheet risk | $ 10,591,000 | $ 15,923,000

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- Definition The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611 + Details
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