CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Statement of Comprehensive Income [Abstract]
Net earnings	$ 463.9	$ 484.2	$ 181.4
Other comprehensive earnings (loss), net of tax
Foreign currency translation adjustments	(59.0)	(93.1)	(27.2)
Unrealized (loss) gain on marketable securities	(2.9)	(0.8)	0.8
Unrealized (loss) gain on hedging instruments	(21.4)	1.2	(3.4)
Net unrealized gain (loss) on benefit plans	95.7	(139.2)	65.1
Other comprehensive earnings (loss), net of tax	12.4	(231.9)	35.3
Comprehensive earnings	$ 476.3	$ 252.3	$ 216.7