Deposits (Composition of Deposits) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Disclosure Composition Of Deposits [Abstract]
Noninterest-bearing deposits	$ 1,017,566,000	$ 993,737,000
Interest-bearing deposits:
Demand	527,801,000us-gaap_DemandDepositAccounts	534,605,000us-gaap_DemandDepositAccounts
Money market savings	836,548,000us-gaap_DepositsMoneyMarketDeposits	828,494,000us-gaap_DepositsMoneyMarketDeposits
Regular savings	277,230,000us-gaap_DepositsSavingsDeposits	264,751,000us-gaap_DepositsSavingsDeposits
Time deposits of less than $100,000	241,084,000us-gaap_TimeDepositsLessThan100000	239,857,000us-gaap_TimeDepositsLessThan100000
Time deposits of $100,000 or more	209,663,000us-gaap_TimeDeposits100000OrMore	205,065,000us-gaap_TimeDeposits100000OrMore
Total interest-bearing deposits	2,092,326,000	2,072,772,000
Total deposits	$ 3,109,892,000us-gaap_Deposits	$ 3,066,509,000us-gaap_Deposits

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The amount of money in accounts that may bear interest and that the depositor is entitled to withdraw at any time without prior notice.

+ References

+ 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.

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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).

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- Definition

The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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+ Details

Name:	us-gaap_InterestBearingDepositLiabilities
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- Details

Name:	us-gaap_InterestBearingDepositLiabilitiesAbstract
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- Definition

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

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+ Details

Name:	us-gaap_NoninterestBearingDepositLiabilities
Namespace Prefix:	us-gaap_
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- Definition

The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 405

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6479006&loc=d3e64164-112818

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Industry Guide

-Number 3

-Section V

-Paragraph A

-Subparagraph 4

+ Details

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- Definition

The aggregate amount of domestic or foreign time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000.

+ References

No definition available.

+ Details

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