Stockholders' Equity - Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	Oct. 31, 2017	Jan. 31, 2017	Oct. 31, 2016
Accumulated other comprehensive (loss) earnings, net of tax:
Foreign currency translation adjustments	$ (102.4)	$ (143.7)	$ (121.7)
Unrealized (loss) gain on marketable securities	(0.8)	0.8	1.0
Deferred hedging loss	(16.5)	(16.1)	(22.0)
Net unrealized loss on benefit plans	(91.2)	(97.2)	(108.5)
Accumulated other comprehensive loss, net of tax	$ (210.9)	$ (256.2)	$ (251.2)