Income Taxes Tax Effects of Temporary Differences and Carryforwards on Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012
Deferred Tax Assets, Net [Abstract]
Depreciation of property, plant, and equipment	$ 274	$ 232
Reserves and allowances	10,398	9,509
Accrued expenses not currently deductible	20,463	22,267
Stock-based compensation expense	12,394	14,902
Net operating loss carryforwards	55,612	68,746
Tax Credit Carryforwards	75,639	57,198
Deferred Tax Assets, Goodwill and Intangible Assets	6,456	15,070
Deferred revenue	3,097	1,563
Other, net	7,853	8,086
Total gross deferred tax assets	192,186	197,573
Less Valuation Allowance	(154,695)	(147,984)
Deferred Tax Assets	37,491	49,589
Deferred Tax Liabilities, Net [Abstract]
Intangible Assets	(9,948)	(21,578)
Deferred Tax Liabilities, Financing Arrangements	13,519	15,607
Deferred Tax Liabilities, Net	23,467	37,185
Deferred Tax Assets, Net	$ 14,024	$ 12,404