Segment Reporting Revenues Related to Operations in Geographic Regions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Revenues:
Total revenues	$ 292,683	$ 275,642	$ 805,067	$ 755,373
UNITED STATES
Revenues:
Total revenues	135,264	135,862	371,722	323,475
Europe
Revenues:
Total revenues	64,936	57,571	180,547	151,979
Japan
Revenues:
Total revenues	25,359	18,911	67,613	62,065
Asia
Revenues:
Total revenues	64,346	60,341	171,022	206,783
Americas [Member]
Revenues:
Total revenues	$ 2,778	$ 2,957	$ 14,163	$ 11,071