Revenue Recognition (Contract Balances) (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2026	Sep. 30, 2025
Assets
Contract assets – current	$ 64.5	$ 152.6
Contract fulfillment costs – current	76.0	85.4
Contract assets – noncurrent	110.0	82.3
Contract fulfillment costs – noncurrent	32.4	33.8
Liabilities
Contract liabilities – current	219.2	253.4
Contract liabilities – noncurrent	278.6	$ 283.6
Revenue recognized that was previously included in current contract liabilities	$ 160.0