Net Earnings Per Common Share (Computations of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Net Earnings Per Common Share
Net earnings (loss)	$ 18.4	$ 2.5
Basic weighted average common shares (in millions)	51.1	52.0
Effect of dilutive securities - dilutive securities	0.7	0.2
Diluted weighted average common shares (in millions)	51.8	52.2
Basic net earnings (loss) per share	$ 0.36	$ 0.05
Diluted net earnings (loss) per share	$ 0.36	$ 0.05