Leases (Minimum Lease Payments Expected to be Collected) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Sep. 30, 2019
Minimum Lease Payments Expected to be Collected on Sales-type and Direct Financing Leases
2020 (excluding the three months ended 31 December)	$ 122.9
2021	159.2
2022	148.3
2023	142.0
2024	135.8
Thereafter	730.2
Total	1,438.4
Unearned interest income	(463.6)
Lease Receivables, net	$ 974.8
Minimum Lease Payments Expected to be Collected Prior to Adoption of New Lease Guidance
2020		$ 162.5
2021		156.9
2022		145.7
2023		139.4
2024		133.2
Thereafter		715.5
Total		1,453.2
Unearned interest income		(472.3)
Lease Receivables, net		$ 980.9