Deposits - Summary of Deposits Including Accrued Interest Payable (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Banking and Thrift [Abstract]
Non-interest-bearing accounts, Amount	$ 279,944	$ 207,608
Interest-bearing checking accounts, Amount	836,120	913,753
Money market deposit accounts, Amount	95,663us-gaap_DepositsMoneyMarketDeposits	116,947us-gaap_DepositsMoneyMarketDeposits
Savings accounts, Amount	301,190us-gaap_DepositsSavingsDeposits	290,512us-gaap_DepositsSavingsDeposits
Time deposits, Amount	207,218us-gaap_TimeDeposits	217,943us-gaap_TimeDeposits
Total deposits	$ 1,720,135us-gaap_Deposits	$ 1,746,763us-gaap_Deposits
Non-interest-bearing accounts, Weighted Average Cost	0.00%	0.00%
Interest-bearing checking accounts, Weighted Average Cost	0.09%	0.12%
Money market deposit accounts, Weighted Average Cost	0.06%	0.12%
Savings accounts, Weighted Average Cost	0.03%	0.05%
Time deposits, Weighted Average Cost	1.45%	1.37%
Weighted Average Cost	0.23%	0.25%

Non Interest Bearing Deposit Liabilities Weighted Average Cost Percentage

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- Details

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- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ 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 210.9-03.12)

-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 12

-Article 9

+ Details

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- Definition

Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.

+ References

+ Details

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- Definition

Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).

+ References

+ Details

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- Definition

Amount of interest-bearing domestic checking deposit liabilities.

+ References

+ Details

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- Definition

The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

+ References

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- Definition

Amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

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- Definition

The weighted average interest rate for all domestic deposit liabilities.

+ References

No definition available.

+ Details

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- Definition

The weighted average interest rate for domestic checking deposit liabilities.

+ References

No definition available.

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- Definition

The weighted average interest rate for domestic money market demand account deposit liabilities.

+ References

No definition available.

+ Details

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- Definition

The weighted average interest rate for domestic savings deposit liabilities.

+ References

No definition available.

+ Details

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- Definition

The weighted average interest rate for domestic time deposit liabilities.

+ References

No definition available.

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