Railcar Leasing and Management Services Group - Future contractual minimum rental revenues on leases (Details) - Railcar Leasing and Management Services Group [Member] $ in Millions	Jun. 30, 2020 USD ($)
Future contractual minimum rental revenue
Operating Leases, Future Minimum Payments Receivable, Remainder of Fiscal Year	$ 298.6
Operating Leases, Future Minimum Payments Receivable, in Two Years	494.0
Operating Leases, Future Minimum Payments Receivable, in Three Years	387.9
Operating Leases, Future Minimum Payments Receivable, in Four Years	280.9
Operating Leases, Future Minimum Payments Receivable, in Five Years	199.8
Thereafter	353.8
Total	2,015.0
Railroad Transportation Equipment
Future contractual minimum rental revenue
Operating Leases, Future Minimum Payments Receivable, Remainder of Fiscal Year	295.0
Operating Leases, Future Minimum Payments Receivable, in Two Years	488.3
Operating Leases, Future Minimum Payments Receivable, in Three Years	384.0
Operating Leases, Future Minimum Payments Receivable, in Four Years	279.2
Operating Leases, Future Minimum Payments Receivable, in Five Years	199.0
Thereafter	353.3
Total	$ 1,998.8