Segment Information - Reconciliation of Segments' Earnings from Operations to Company's Consolidated Earnings from Operations Before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Segment Reporting [Abstract]
Earnings from operations for segments	$ 222.5	$ 242.0	$ 428.7	$ 486.1
Unallocated corporate expenses	(40.1)	(33.5)	(76.3)	(67.8)
Interest and other expenses, net	(13.6)	(16.1)	(22.9)	(32.4)
Other Operating Expense	(9.6)	0.0	(9.6)	0.0
Earnings from operations before income taxes	$ 159.2	$ 192.4	$ 319.9	$ 385.9