Segment Reporting (Revenues and Operating Earnings Based on Originating Location) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended								12 Months Ended
	Jan. 31, 2015	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2017	Jan. 31, 2016	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 133.0	$ 373.4	$ 389.0	$ 378.9	$ 352.8	$ 358.2	$ 365.0	$ 412.7	$ 431.5	$ 1,494.1	$ 1,567.4	$ 1,695.7
Operating earnings	17.7									129.4	(536.8)	246.8
Identifiable assets	4,224.6	3,698.3				3,691.0				3,698.3	3,691.0	4,280.6
Domestic
Segment Reporting Information [Line Items]
Revenues	124.1									1,423.8	1,453.4	1,505.3
Operating earnings	15.0									109.3	(561.0)	195.5
Identifiable assets		3,214.1				3,182.2				3,214.1	3,182.2
Foreign
Segment Reporting Information [Line Items]
Revenues	8.9									70.3	114.0	190.4
Operating earnings	$ 2.7									20.1	24.2	$ 51.3
Identifiable assets		$ 484.2				$ 508.8				$ 484.2	$ 508.8