Quarterly Financial Data (Unaudited) Text (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			12 Months Ended
	Jan. 31, 2016	Jul. 31, 2015	Oct. 31, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Loan impairment charges	$ 28.3	$ 9.6		$ 37.9	$ 0.0	$ 0.0
Loan impairment charges per share impact	$ 0.14	$ 0.05
Loss on Extinguishment of Debt			$ (93.8)	0.0	(93.8)	0.0
Arbitration award expense				$ 0.0	$ 0.0	480.2
Transaction Gain Related to Arbitration Award						$ 7.5
Diluted				129.1	129.9	128.9
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount				0.8	0.3	0.4
Loss on extinguishment of debt per share impact			$ 0.47
Repayment of Long-term Debt				$ 0.0	$ 400.0	$ 0.0
Cost reduction initiatives expense	$ 8.8
Cost reduction initiatives per share impact	$ 0.04