Property and Equipment at Cost (Detail) (USD $) In Thousands, unless otherwise specified					12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014 Machinery and equipment	Jan. 31, 2013 Machinery and equipment	Jan. 31, 2014 Machinery and equipment Minimum	Jan. 31, 2014 Machinery and equipment Maximum	Jan. 31, 2014 Leasehold improvements	Jan. 31, 2013 Leasehold improvements	Jan. 31, 2014 Leasehold improvements Minimum	Jan. 31, 2014 Leasehold improvements Maximum	Jan. 31, 2014 Furniture and fixtures	Jan. 31, 2013 Furniture and fixtures	Jan. 31, 2014 Furniture and fixtures Minimum	Jan. 31, 2014 Furniture and fixtures Maximum	Jan. 31, 2014 Computer equipment and software	Jan. 31, 2013 Computer equipment and software	Jan. 31, 2014 Computer equipment and software Minimum	Jan. 31, 2014 Computer equipment and software Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of fixed assets					4 years	5 years			1 year	19 years			3 years	10 years			2 years	5 years
Property and equipment, gross	$ 101,206	$ 68,812	$ 2,077	$ 2,086			$ 60,817	$ 44,656			$ 30,883	$ 17,047			$ 7,429	$ 5,023
Less: accumulated depreciation	38,374	27,996
Property and equipment, net	$ 62,832	$ 40,816