Other Borrowings - Summary of Balances of Other Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total other borrowings	$ 9,096us-gaap_OtherBorrowings	$ 9,276us-gaap_OtherBorrowings
Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014 [Member]
Debt Instrument [Line Items]
Other collateralized borrowings, fixed rate, as of March 31, 2015 of 0.05%, payable on April 1, 2015	$ 9,096	$ 9,276

The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

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 210.9-03.13,16)

-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 13, 16

-Article 9

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