Loans Receivable, Net - Aging of Recorded Investment in Past Due Loans (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	$ 8,329	$ 8,348
60-89 Days Past Due	1,927	3,781
Greater than 90 Days Past Due	16,767	39,556
Total Past Due	27,023	51,685
Loans Not Past Due	1,691,664	1,519,894
Total loans	1,718,687	1,571,579
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	785,441	781,406
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	649,951	528,945
Residential [Member] \| Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	7,365	6,304
60-89 Days Past Due	1,695	2,634
Greater than 90 Days Past Due	1,619	25,296
Total Past Due	10,679	34,234
Loans Not Past Due	727,210	716,350
Total loans	737,889	750,584
Residential Construction [Member] \| Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due		195
Total Past Due		195
Loans Not Past Due	47,552	30,626
Total loans	47,552	30,821
Commercial [Member] \| Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	119	985
60-89 Days Past Due		849
Greater than 90 Days Past Due	12,558	9,217
Total Past Due	12,677	11,051
Loans Not Past Due	587,387	491,817
Total loans	600,064	502,868
Construction and Land [Member] \| Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days Past Due	200	309
Total Past Due	200	309
Loans Not Past Due	49,687	25,769
Total loans	49,887	26,078
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	845	864
60-89 Days Past Due	232	298
Greater than 90 Days Past Due	1,833	4,219
Total Past Due	2,910	5,381
Loans Not Past Due	196,439	195,302
Total loans	199,349	200,683
Consumer [Member] \| Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	199,349	200,683
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days Past Due	557	515
Total Past Due	557	515
Loans Not Past Due	83,389	60,030
Total loans	$ 83,946	$ 60,545

Financing receivables that are less than 60 days past due but more than 29 days past due.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7A

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524

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Financing receivables that are less than 90 days past due but more than 59 days past due.

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Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5111-111524

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Financing receivables that are current.

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Recorded Investment in financing receivables that are past due at the balance sheet date.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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