Supplementary Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2016	Sep. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Allowance for possible losses and discounts on trade receivables	$ 26.9	$ 26.8
Inventories:
Finished products	116.7	124.2
Raw materials and work in process	128.9	127.8
Total inventory	245.6	252.0
Accumulated depreciation of property, plant and equipment	616.2	611.8
Accumulated amortization of software and other intangible assets	$ 422.4	$ 398.3
Preferred stock, without par value:
Shares authorized (in shares)	1,000,000	1,000,000
Shares issued (in shares)	0	0
Common stock, without par value:
Shares authorized (in shares)	199,000,000	199,000,000
Shares issued (in shares)	88,457,634	88,457,634
Shares outstanding (in shares)	65,336,428	65,705,253
Treasury shares (in shares)	23,121,206	22,752,381