Segment Information - Company's Segments Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 30, 2015	Apr. 30, 2014
Net sales:
Net sales	$ 962.4	$ 1,012.1
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	206.2	244.1
Americas [Member]
Net sales:
Net sales	443.7	438.7
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	72.3	81.5
Asia-Pacific [Member]
Net sales:
Net sales	259.0	260.9
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	72.7	71.8
Japan [Member]
Net sales:
Net sales	121.8	173.9
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	43.8	71.5
Europe [Member]
Net sales:
Net sales	102.9	101.3
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	14.0	17.0
Reportable Geographical Components [Member]
Net sales:
Net sales	927.4	974.8
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	202.8	241.8
Other [Member]
Net sales:
Net sales	35.0	37.3
Earnings (losses) from operations:
Segment Reporting Earnings Losses From Continuing Operations Before Unallocated Corporate Expenses Interest	$ 3.4	$ 2.3