Revenue - Unearned Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Unearned Revenue (Details)
Unearned Revenue	$ 35.0	$ 23.0	$ 27.9	$ 21.6
Contract with Customer, Liability, Revenue Recognized	$ 7.4	$ 6.1