Pension Plans (Schedule of Allocation of Plan Assets) (Details) - Pension Plan - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
United States
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	$ 356.9	$ 490.1	$ 491.7
United States | Fair Value, Inputs, Level 1, 2 and 3 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	32.5	60.0
United States | Fair Value, Inputs, Level 1, 2 and 3 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	1.2	3.4
United States | Fair Value, Inputs, Level 1, 2 and 3 | U.S. Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	241.4	292.8
United States | Fair Value, Inputs, Level 1, 2 and 3 | Other Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Fair Value, Inputs, Level 1, 2 and 3 | CASH & CASH EQUIVALENTS
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	15.0	3.5
United States | Fair Value, Inputs, Level 1, 2 and 3 | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	33.7	63.4
United States | Level 1 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	32.5	60.0
United States | Level 1 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	1.2	3.4
United States | Level 1 | U.S. Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 1 | Other Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 1 | CASH & CASH EQUIVALENTS
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 1 | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	256.4	296.3
United States | Level 2 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 2 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 2 | U.S. Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	241.4	292.8
United States | Level 2 | Other Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Level 2 | CASH & CASH EQUIVALENTS
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	15.0	3.5
United States | Level 2 | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Assets Measured at Net Asset Value | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	34.0	76.8
United States | Assets Measured at Net Asset Value | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	32.8	53.6
United States | Assets Measured at Net Asset Value | Corporate
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
United States | Assets Measured at Net Asset Value | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	78.3	133.1	$ 124.5
International Pension Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	7.4	9.9
International Pension Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | U.S. Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | Other Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	16.0	22.5
International Pension Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | CASH & CASH EQUIVALENTS
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	3.5	2.6
International Pension Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	7.0	7.0
International Pension Plan Assets | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 1 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 1 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 1 | U.S. Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 1 | Other Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 1 | CASH & CASH EQUIVALENTS
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 1 | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	33.9	42.0
International Pension Plan Assets | Level 2 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 2 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	7.4	9.9
International Pension Plan Assets | Level 2 | U.S. Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Level 2 | Other Government
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	16.0	22.5
International Pension Plan Assets | Level 2 | CASH & CASH EQUIVALENTS
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	3.5	2.6
International Pension Plan Assets | Level 2 | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	7.0	7.0
International Pension Plan Assets | Assets Measured at Net Asset Value | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	0.0	0.0
International Pension Plan Assets | Assets Measured at Net Asset Value | International Equity
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	10.2	28.3
International Pension Plan Assets | Assets Measured at Net Asset Value | Corporate
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	20.0	41.3
International Pension Plan Assets | Assets Measured at Net Asset Value | OTHER
Defined Benefit Plan Disclosure [Line Items]
Assets at estimated fair value	$ 14.2	$ 21.5