Railcar Leasing and Management Services Group - Future operating lease obligations and future contractual minimum rental revenues (Details) - Railcar Leasing and Management Services Group $ in Millions	Sep. 30, 2017 USD ($)
Railroad transportation equipment leased from independent owner trusts
Future operating lease obligations
Remaining three months of 2017	$ 7.3
2018	29.2
2019	28.8
2020	26.1
2021	26.1
Thereafter	118.0
Total	235.5
Future contractual minimum rental revenues
Remaining three months of 2017	11.1
2018	36.5
2019	25.7
2020	16.1
2021	11.3
Thereafter	15.5
Total	116.2
Operating leases other than leases with the Trusts
Future operating lease obligations
Remaining three months of 2017	2.9
2018	12.0
2019	9.5
2020	7.7
2021	7.6
Thereafter	13.4
Total	53.1
Future contractual minimum rental revenues
Remaining three months of 2017	3.1
2018	9.2
2019	6.8
2020	4.5
2021	3.3
Thereafter	4.1
Total	$ 31.0