Stockholders' Equity - Additions to and Reclassifications out of Accumulated Other Comprehensive (Loss) Earnings (Details) - USD ($) $ in Millions		3 Months Ended
		Apr. 30, 2019	Apr. 30, 2018
Equity [Abstract]
Foreign currency translation adjustments		$ (21.8)	$ (25.4)
Income tax (expense) benefit		2.4	(0.4)
Foreign currency translation adjustments, net of tax		(24.2)	(25.0)
Unrealized gain (loss) on hedging instruments		17.7	(7.2)
Reclassification adjustment for gain included in net earnings	[1]	7.6	2.3
Income tax (expense) benefit		1.3	(2.2)
Unrealized gain (loss) on hedging instruments, net of tax		8.8	(7.3)
Amortization of net loss included in net earnings	[2]	2.8	3.3
Amortization of prior service credit included in net earnings	[2]	(0.2)	(0.2)
Income tax expense		(0.4)	(0.7)
Net unrealized gain on benefit plans, net of tax		(2.2)	(2.4)
Total other comprehensive loss, net of tax		$ (13.2)	$ (29.9)

[1] These gains are reclassified into Cost of sales, Interest expense and financing costs and Other (income) expense, net (see "Note 8. Hedging Instruments" for additional details).

[2] These losses (gains) are included in the computation of net periodic benefit cost (see "Note 13. Employee Benefit Plans" for additional details) and are reclassified into Other (income) expense, net.