Railcar Leasing and Management Services Group - Narrative (Details) - Railcar Leasing and Management Services Group [Member] $ in Millions	Jun. 30, 2021 USD ($)
Minimum
Segment Reporting Information [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Maximum
Segment Reporting Information [Line Items]
Lessor, Operating Lease, Term of Contract	10 years
Wholly-owned subsidiaries
Segment Reporting Information [Line Items]
Net book value of unpledged equipment	$ 1,109.8
Wholly-owned subsidiaries | Secured Debt [Member]
Segment Reporting Information [Line Items]
Debt Instrument, Collateral Amount	4,731.0
TRIP Holdings [Member] | Secured Debt [Member]
Segment Reporting Information [Line Items]
Debt Instrument, Collateral Amount	1,137.2
RIV 2013 Holdings | Secured Debt [Member] | TRL 2012 Secured Railcar Equipment Notes - RIV 2013 [Member]
Segment Reporting Information [Line Items]
Debt Instrument, Collateral Amount	$ 468.4