Income Taxes (Reconciliation) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2017	Jan. 31, 2016	Dec. 31, 2014
Income Taxes
Statutory U.S. federal income tax rate		35.00%
Statutory federal income tax (benefit) expense	$ 4.0	$ 18.7	$ (214.9)	$ 85.3
U.S. state income taxes	0.3	1.5	(17.5)	6.0
Foreign tax rate differential	0.8	0.1	(0.2)	(3.7)
Change in unrecognized tax benefits		(7.8)	0.4
Change in valuation allowance on foreign interest loss carryforwards		(1.6)	5.3
Other, net	(0.8)	1.3	2.0	0.8
Non-taxable/non-deductible items		(6.9)	(3.4)
Exit taxes				67.3
Total income tax (benefit) expense	$ 4.3	$ 5.3	$ (228.3)	$ 155.7