Income Taxes (Details 2) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014
Current deferred income tax assets:
Compensation and benefits	$ 28.4	$ 33.7
Product warranty costs	10.3	12.3
Inventory	15.3	18.3
Allowance for doubtful accounts	8.8	8.8
Deferred credits	9.2	7.5
Returns, rebates and incentives	50.8	54.5
Self-insurance reserves	0.6	0.9
Restructuring reserves	2.6	2.1
Net operating loss carryforwards	3.3	3.5
U.S. federal tax credit carryforwards	0.0	0.2
Other — net	21.9	21.7
Current deferred income tax assets	151.2	163.5
Long-term deferred income tax assets (liabilities):
Retirement benefits	371.2	240.4
Property	(74.9)	(81.9)
Intangible assets	(53.2)	(50.2)
Environmental reserves	15.9	16.9
Share-based compensation	35.5	32.6
Self-insurance reserves	9.4	7.9
Deferred gains	2.0	2.4
Net operating loss carryforwards	22.6	31.9
Capital loss carryforwards	13.6	14.8
U.S. federal tax credit carryforwards	1.2	1.3
State tax credit carryforwards	7.3	5.8
Other — net	15.2	11.6
Subtotal	365.8	233.5
Valuation allowance	(22.2)	(27.8)
Net long-term deferred income tax assets	343.6	205.7
Total net deferred income tax assets	$ 494.8	$ 369.2