Other Comprehensive Income - Changes in Balances of Each Component of Other Comprehensive Income Included in Accumulated Other Comprehensive Income (Detail) (USD $)	3 Months Ended	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period		$ 247,000
Amounts reclassified from accumulated OCI	(43,000)	(43,000)
Balance at end of period	368,000	368,000
Net Unrealized Gain (Loss) on Available-for Sale Securities in Supplemental Executive Retirement Plan
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period		247,000
Other comprehensive income before reclassifications		164,000
Amounts reclassified from accumulated OCI		(43,000)
Balance at end of period	$ 368,000	$ 368,000