Fair Value Measurements (Schedule of Nonrecurring Fair Value Measurements) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024
Long Lived Assets Held-for-sale [Line Items]
Plant and equipment, net	$ 25,640.0		$ 23,370.9
Fair Value, Nonrecurring | Project Exit Costs
Long Lived Assets Held-for-sale [Line Items]
Plant and equipment, net	22.5	$ 22.5
Impairment of property and equipment	1,752.0	1,752.0
Fair Value, Nonrecurring | Level 3 | Project Exit Costs
Long Lived Assets Held-for-sale [Line Items]
Plant and equipment, net	$ 22.5	$ 22.5