Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013	Jan. 31, 2013
Other intangible assets
Gross	$ 484,240	$ 484,124
Accumulated Amortization	(448,049)	(438,463)
Net	36,191	45,661
Technology, licenses and patents [Member]
Other intangible assets
Gross	184,213	184,213
Accumulated Amortization	(179,597)	(179,159)
Net	4,616	5,054
Customer relationships [Member]
Other intangible assets
Gross	278,900	278,900
Accumulated Amortization	(249,294)	(240,663)
Net	29,606	38,237
Trademarks [Member]
Other intangible assets
Gross	14,300	14,300
Accumulated Amortization	(12,778)	(12,334)
Net	1,522	1,966
Internal-use software [Member]
Other intangible assets
Gross	6,827	6,711
Accumulated Amortization	(6,380)	(6,307)
Net	$ 447	$ 404