Revenue Recognition (Contract Assets and Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2025	Sep. 30, 2025
Contract Assets and Liabilities
Contract assets – current	$ 142.0	$ 152.6
Contract fulfillment costs – current	91.5	85.4
Contract assets – noncurrent	102.5	82.3
Contract fulfillment costs – noncurrent	37.1	33.8
Contract liabilities – current	250.2	253.4
Contract liabilities – noncurrent	281.8	$ 283.6
Revenue recognized that was previously included in current contract liabilities	$ 30.0