Summary of Level 3 Activity (Detail) $ in Thousands	6 Months Ended
	Jul. 31, 2016 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 3,749
Payments	(1,475)
Adjustment	34
Interest accretion	58
Balance at ending of period	$ 2,366