Loans - Recorded Investment in Residential, Consumer and Credit Card Loans Based on Payment Activity (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Residential real estate	$ 477,186	$ 459,114
Consumer	65,314	63,491
Credit cards	5,115	5,065
Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Residential real estate	472,246	456,575
Consumer	64,298	62,379
Credit cards	5,062	5,041
Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Residential real estate	4,940	2,539
Consumer	1,016	1,112
Credit cards	$ 53	$ 24

Amount before allowance of credit card loans issued to individuals. 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.

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph a, b

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph a

-Article 9

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(a)(4),(b))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_LoansAndLeasesReceivableConsumerRevolvingCreditCard
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant