Employee Benefit Plans Reconcilation of Benefit Obligations, Plan Assets and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at beginning of the year	$ 530.1
Fair Value of Plan Assets at end of year	578.1	$ 530.1
Pension Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at beginning of year	783.7	742.6
Service cost	17.3	17.4	$ 22.6
Interest cost	32.0	31.6	30.6
Participants' contributions	0.0	0.0
MMA retiree drug subsidy	0.0	0.0
Actuarial loss (gain)	21.1	15.9
Benefits paid	59.4	24.3
Translation	0.9	0.5
Benefit Obligation at end of year	795.6	783.7	742.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at beginning of the year	530.1	385.8
Actual Return on Plan Assets	86.1	42.9
Employer Contribution	21.3	125.7
Participants' contributions	0.0	0.0
MMA retiree drug subsidy	0.0	0.0
Benefits paid	59.4	24.3
Fair Value of Plan Assets at end of year	578.1	530.1	385.8
Funded Status	(217.5)	(253.6)
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation at beginning of year	72.5	78.4
Service cost	2.8	2.8	4.2
Interest cost	3.0	3.1	3.2
Participants' contributions	1.0	1.2
MMA retiree drug subsidy	0.2	0.0
Actuarial loss (gain)	1.5	(10.5)
Benefits paid	2.5	2.5
Translation	0.0	0.0
Benefit Obligation at end of year	78.5	72.5	78.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at beginning of the year	0.0	0.0
Actual Return on Plan Assets	0.0	0.0
Employer Contribution	1.3	1.3
Participants' contributions	1.0	1.2
MMA retiree drug subsidy	0.2	0.0
Benefits paid	2.5	2.5
Fair Value of Plan Assets at end of year	0.0	0.0	$ 0.0
Funded Status	$ (78.5)	$ (72.5)