Summary of Significant Accounting Policies Carrying Value of Goodwill, Intangible Assets, and Long-lived Assets (Parenthetical) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Purchased Technology and In-Process Research and Development
Goodwill And Intangible Assets Disclosure
Intangible assets, accumulated amortization	$ 124,536	$ 121,011
Other Intangible Assets
Goodwill And Intangible Assets Disclosure
Intangible assets, accumulated amortization	$ 71,216	$ 65,049