Schedule of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Jan. 31, 2013
Property Plant And Equipment [Abstract]
Land	$ 248,263	$ 248,263
Building improvements	49,572	49,572
Computers, equipment and software	877,175	328,318
Furniture and fixtures	51,687	38,275
Leasehold improvements	252,828	193,181
Property, Plant and Equipment, Gross, Total	1,479,525	857,609
Less accumulated depreciation and amortization	(294,664)	(252,940)
Property and equipment, net	$ 1,184,861	$ 604,669