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Hedging Activities - Additional Information (Detail) (USD $) | 1 Months Ended | 9 Months Ended |  |  |  | 1 Months Ended
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Jun. 30, 2011 | Sep. 30, 2013 | Dec. 31, 2012 | Feb. 29, 2012 | Jun. 30, 2011 Interest rate cap contracts [Member] | Feb. 29, 2012 Basis Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |  |  |  |
Notional amounts of interest rate swap agreement and purchased interest rate cap |  |  |  |  | $ 100,000,000 | $ 32,000,000
Notional amount of sold interest rate cap | 100,000,000 |  |  |  |  |
Rate used to determine payment received from correspondent bank on notional amount of interest rate swap/Basis for determining strike rate on purchased interest rate cap | 30-Day Libor rate |  |  |  |  | 90-Day Libor Rate
Strike rate of sold interest rate cap in basis points above strike rate on purchased interest rate cap | 1.25% |  |  |  |  |
Fixed spread added to the variable rate on our subordinated debentures |  |  |  |  |  | 2.18%
Subordinated debentures interest rate index |  |  |  |  |  | 90-Day Libor Rate
Subordinated debentures |  |  |  | 32,000,000 |  |
Present value of Interest rate swap, record as liability |  | 400,000 | 1,100,000 |  |  |
Cap corridor maturity |  | 2013-06 |  |  |  |
Interest rate swap agreement effective date |  | 2013-01 |  |  |  |
Interest rate swap agreement maturity date |  | 2018-01 |  |  |  |
Payment made under interest rate cap contract |  | $ 0 |  |  |  |

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition Debt instrument descriptions of variable rate basis. + References No definition available. + Details
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- Definition Fair value of interest rate swap agreement liability. + References No definition available. + Details
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- Definition Hedging activities interest rate cap agreement maturity month year. + References No definition available. + Details
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- Definition Hedging activities interest rate swap agreement effective date. + References No definition available. + Details
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- Definition Hedging activities interest rate swap agreement maturity date. + References No definition available. + Details
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- Definition Notional amount of sold interest rate cap. + References No definition available. + Details
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- Definition Payment made under interest rate cap contract. + References No definition available. + Details
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- Definition The percentage points added to the reference rate to compute the variable rate on the interest rate derivative. + References No definition available. + Details
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- Definition Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract. + References No definition available. + Details
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- Definition The reference rate for the variable rate of the interest rate derivative, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
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- Details
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- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section F Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Article 5 -Subsection 19, 20, 22 + Details
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