Commitments And Contingencies (Narrative) (Details) $ in Millions	3 Months Ended
Apr. 30, 2016 USD ($) landfill
Redfield Site [Member]
Loss Contingencies [Line Items]
Cumulative expenditures for both on-site and off-site remediation	$ 28.0
Reserve for anticipated future remediation activities	9.9
Reserve for anticipated future remediation activities for on-site remediation	5.0
Reserve for anticipated future remediation activities for off-site remediation	$ 4.9
Liability for on-site remediation, discounted rate	4.80%
On-site remediation liability, undiscounted basis	$ 15.1
Expected on-site remediation liability, year one	0.4
Expected on-site remediation liability, year two	0.3
Expected on-site remediation liability, year three	0.1
Expected on-site remediation liability, year four	0.1
Expected on-site remediation liability, year five	0.2
Expected on-site remediation liability, thereafter	14.0
Redfield Site Other Liabilities [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies in other liabilities	9.1
Redfield Site Other Accrued Expense [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies in other accrued expenses	0.8
New York Tannery And Two Associated Landfills [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies in other liabilities	1.0
Accrual for environmental loss contingencies in other accrued expenses	$ 0.2
Liability for on-site remediation, discounted rate	6.40%
Expected on-site remediation liability, year one	$ 0.2
Expected on-site remediation liability, year two	0.2
Expected on-site remediation liability, year three	0.2
Expected on-site remediation liability, year four	0.2
Expected on-site remediation liability, year five	0.2
Expected on-site remediation liability, thereafter	$ 0.4
Number of associated landfills for which remediation efforts are completed \| landfill	2
Accrued liability to complete the cleanup, maintenance and monitoring at all sites	$ 1.2
Accrued liability on an undiscounted basis	$ 1.4

Accrual for environmental loss contingencies in other accrued expenses.

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Accrual for environmental loss contingencies in other liabilities.

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Cumulative environmental remediation expense.

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Remediation efforts completed for number of associated landfills.

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Reserve for anticipated future remediation activities.

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Reserve for anticipated future remediation activities for off site remediation.

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Site contingency accrual on an undiscounted basis.

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Total costs accrued as of the balance sheet date for environmental loss contingencies.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Undiscounted amount of the accrual for environmental loss contingencies expected to be paid in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Undiscounted amount of the accrual for environmental loss contingencies expected to be paid in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Undiscounted amount of the accrual for environmental loss contingencies expected to be paid in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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