Segment Reporting Revenues Related to Operations in Geographic Regions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2014	Apr. 30, 2013
Revenues:
Total revenues	$ 252,151	$ 226,515
UNITED STATES
Revenues:
Total revenues	124,766	96,086
Europe
Revenues:
Total revenues	60,149	48,707
Japan
Revenues:
Total revenues	21,281	26,677
Asia
Revenues:
Total revenues	43,713	51,991
Other North America
Revenues:
Total revenues	$ 2,242	$ 3,054