Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Deferred income tax assets:
Inventory reserves	$ 4.6	$ 11.7
Accrued expenses	12.2	10.0
Pension and other postretirement benefits	0.2	1.7
Stock-based compensation	2.6	2.7
State net operating losses	3.0	2.8
Federal net operating losses and credit carryovers	3.0	2.8
Deferred Tax Assets Leasing Liabilities	7.3	0.0
All other	1.1	2.4
Deferred income tax assets	34.0	34.1
Valuation allowance	(2.9)	(2.8)
Total deferred income tax assets	31.1	31.3
Deferred income tax liabilities:
Identifiable intangible assets	(90.2)	(95.6)
Pension and other postretirement benefits	5.0	4.7
Deferred Tax Liabilities, Leasing Arrangements	6.6	0.0
Other	(25.6)	(18.9)
Total deferred income tax liabilities	127.4	119.2
Net deferred income tax liabilities	96.3	87.9
Deferred Tax Liabilities, Gross, Noncurrent	$ 96.5	$ 87.9