Segment Reporting Revenues Related to Operations in Geographic Regions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2015	Apr. 30, 2014
Revenues:
Total revenues	$ 272,143	$ 252,151
UNITED STATES
Revenues:
Total revenues	129,191	124,766
Europe
Revenues:
Total revenues	46,319	60,149
Japan
Revenues:
Total revenues	21,417	21,281
Asia
Revenues:
Total revenues	70,129	43,713
Americas [Member]
Revenues:
Total revenues	$ 5,087	$ 2,242