Net Earnings Per Common Share (Computations of Basic and Diluted Earnings Per Share) (Details 2) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Apr. 30, 2016	Apr. 30, 2015
Net Earnings Per Common Share
Net earnings (loss)	$ 6.2	$ 17.9
Weighted average common shares - basic	52.0	52.2
Effect of restricted shares issued	0.2	0.1
Weighted average common shares - diluted	52.2	52.3
Net earnings per share - basic	$ 0.12	$ 0.34
Net earnings per share - diluted	$ 0.12	$ 0.34