Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
Jan. 31, 2016	Jan. 31, 2015
Postemployment Benefits [Abstract]
Contribution to the ESOP	$ 0	$ 100,000
Contributions paid or accrued amounted	$ 306,000	$ 294,000

This item represents the amount of cash contributions during the period made by the entity to the Employee Stock Ownership Plan (ESOP).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

Name:	us-gaap_EmployeeStockOwnershipPlanESOPCashContributionsToESOP
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration