Segment Information Sales to Unaffiliated Customers and Long-Lived Assets by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended											12 Months Ended
	Jan. 31, 2016		Oct. 31, 2015	Jul. 31, 2015	[2]	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	[3]	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,213.6	[1]	$ 938.2	$ 990.5		$ 962.4	$ 1,285.3	$ 959.6		$ 992.9	$ 1,012.1	$ 4,104.9	$ 4,249.9	$ 4,031.1
Long-Lived Assets	984.2						943.7					984.2	943.7	896.4
UNITED STATES [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales												1,795.5	1,870.8	1,770.7
Long-Lived Assets	706.9						680.1					706.9	680.1	632.9
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales												541.3	554.3	578.6
Long-Lived Assets	20.6						24.4					20.6	24.4	21.6
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales												1,768.1	1,824.8	1,681.8
Long-Lived Assets	$ 256.7						$ 239.2					$ 256.7	$ 239.2	$ 241.9

[1] On a pre-tax basis, includes charges for the quarter ended January 31, 2016 of: i.$28.3 million, which reduced net earnings per diluted share by $0.14, associated with an impairment charge related to a financing arrangement with Koidu Limited (see "Note B - Summary of Significant Accounting Policies" and "Note J - Commitments and Contingencies"); andii.$8.8 million, which reduced net earnings per diluted share by $0.04, associated with severance related to staffing reductions and subleasing of certain office space for which only a portion of the Company's future rent obligations will be recovered (see "Note J - Commitments and Contingencies").

[2] On a pre-tax basis, includes a charge of $9.6 million for the quarter ended July 31, 2015, which reduced net earnings per diluted share by $0.05, associated with an impairment charge related to a financing arrangement with Koidu Limited (see "Note B - Summary of Significant Accounting Policies" and "Note J - Commitments and Contingencies").

[3] On a pre-tax basis, includes a charge of $93.8 million for the quarter ended October 31, which reduced net earnings per diluted share by $0.47, associated with the redemption of $400.0 million in aggregate principal amount of the Private Placement Notes prior to their scheduled maturities (see "Note G - Debt").