Restricted Shares Issued in Conjunction with Stock Plan (Detail) - Restricted Stock $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($) shares
Period 1
Class of Stock [Line Items]
Issuance Date	Feb. 04, 2013
Shares \| shares	21,240
Aggregate Market Value \| $	$ 0.6
Period 2
Class of Stock [Line Items]
Issuance Date	Jan. 31, 2014
Shares \| shares	35,500
Aggregate Market Value \| $	$ 1.1
Period 3
Class of Stock [Line Items]
Issuance Date	Jan. 26, 2015
Shares \| shares	40,010
Aggregate Market Value \| $	$ 1.5

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration