Loans - Major Components of Loans (Parenthetical) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Consumer loans, net of discounts	$ 10,797	$ 17,764
Nonfarm, Nonresidential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonfarm, nonresidential loans, net of discounts	$ 136,784	$ 22,001

Reflects the cumulative amount of interest and fees paid by consumer loan borrowers which have not yet been taken into income in conformity with GAAP. Also reflects the amount of unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans which have been classified as consumer loans by the entity and that are being amortized into income as an adjustment to yield.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5074-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(4)

-URI http://asc.fasb.org/extlink&oid=25496975&loc=d3e45377-112738

Name:	us-gaap_LoansAndLeasesReceivableDeferredIncomeConsumer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant