Income Taxes - Additional Information (Detail) (USD $)	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Jan. 31, 2013
Income Tax Disclosure [Abstract]
Prepaid income taxes	$ 1,975,000		$ 5,591,000
Prepaid foreign taxes	400,000		4,200,000
Prepaid domestic federal and state taxes	1,600,000		1,400,000
Net reduction in consolidated income tax expenses		141,000
Recognized tax benefit		3,300,000
Reversed estimates of potential penalties and interest		$ 1,900,000
Effective tax rate without impact	22.40%	17.90%
Federal statutory rate	34.00%