Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at end of period	$ 30,369	$ 20,789
Deferred Tax Assets Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	20,789	19,965	12,254
Additions, Charged to costs and expenses	9,580	824	7,711
Balance at end of period	30,369	20,789	19,965
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	327	946	1,127
Additions, Charged to costs and expenses	80	286
Additions, Charged to other accounts		31	13
Deductions and write-offs	(7)	(936)	(194)
Balance at end of period	$ 400	$ 327	$ 946