Railcar Leasing and Management Services Group - Future contractual minimum rental revenues on leases (Details) - Railcar Leasing and Management Services Group - Railroad Transportation Equipment $ in Millions	Dec. 31, 2018 USD ($)
Property Subject to or Available for Operating Lease [Line Items]
Operating Leases, Future Minimum Payments Receivable, Remainder of Fiscal Year	$ 541.8
Operating Leases, Future Minimum Payments Receivable, in Four Years	251.3
Total	2,028.9
Operating Leases, Future Minimum Payments Receivable, in Two Years	445.2
Operating Leases, Future Minimum Payments Receivable, in Three Years	333.1
Operating Leases, Future Minimum Payments Receivable, in Five Years	160.2
Operating Leases, Future Minimum Payments Receivable, Thereafter	$ 297.3