Segment Reporting Revenues Related to Operations in Geographic Regions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Revenues:
Total revenues	$ 226,515	$ 247,918
North America [Member]
Revenues:
Total revenues	99,140	129,110
Europe [Member]
Revenues:
Total revenues	48,707	52,631
JAPAN
Revenues:
Total revenues	26,677	24,983
Pacific Rim [Member]
Revenues:
Total revenues	$ 51,991	$ 41,194