Restructuring (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Oct. 31, 2011
Restructuring Cost and Reserve [Line Items]
Severance and facilities-related cost in Phase II	$ 7.5
Severance and facilities-related cost paid during period for Phase II	8.8
Severance cost expected to be paid in the current year for Phase II	1.1
Netcentrex 2010 Initiative [Member]
Restructuring Cost and Reserve [Line Items]
Severance and facilities-related cost in Phase II	7.1
Severance and facilities-related cost paid during period for Phase II	6.2
Remaining costs of Netcentrex restructuring plan	$ 4.0