Segment Reporting Revenues Related to Operations in Geographic Regions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Revenues:
Total revenues	$ 275,642	$ 268,760	$ 755,373	$ 757,489
North America
Revenues:
Total revenues	138,819	125,809	334,546	356,472
Europe
Revenues:
Total revenues	57,571	58,937	151,979	165,532
Japan
Revenues:
Total revenues	18,911	23,602	62,065	86,766
Asia
Revenues:
Total revenues	$ 60,341	$ 60,412	$ 206,783	$ 148,719