Restructuring (Narrative) (Details) (USD $) In Millions	6 Months Ended
	Jul. 31, 2011
Severance-related cost in Phase II	$ 6.1
Severance cost paid during period for Phase II	5.8
Severance cost expected to be paid in the current year for Phase II	0.3
Netcentrex 2010 Initiative [Member]
Severance-related cost in Phase II	7.3
Severance cost paid during period for Phase II	1.3
Remaining costs of Netcentrex Restructuring Plan	6.0
Remaining liability of restructuring plan	$ 0.2