Other Borrowings - Additional Information (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Debt Disclosure [Abstract]
Outstanding borrowings	$ 147,409,000	$ 194,572,000	$ 5,000,000
Borrowing available with FHLB	320,800,000
Credit arrangements for federal funds purchase	60,000,000
Loans pledged at federal reserve discount window	584,100,000
Loans pledged at federal reserve discount window available for borrowing	$ 425,100,000

Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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

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Balance Type:	credit
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