Supplemental Information (Change in Estimates) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Change in Accounting Estimate [Line Items]
Operating income (loss)	$ 627.4	$ 577.1	$ 1,712.3	$ 1,664.7
Contracts accounted for under percentage of completion
Change in Accounting Estimate [Line Items]
Operating income (loss)			$ 30.0	$ 26.0