Debt - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Corporate Segment [Member] | Senior Notes due 2028 | 7.75% Senior Notes Due 2028
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.75%
Payments of Debt Issuance Costs	$ 5.5
Debt Instrument, Face Amount	$ 400.0
Corporate Segment [Member] | Senior Notes due 2024 | 4.55% Senior Notes Due October 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.55%
Corporate Segment [Member] | Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 600.0	$ 450.0
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases	100.0
Payments of Debt Issuance Costs	0.7
Proceeds from Lines of Credit	315.0
Repayments of Lines of Credit	540.0
Line of Credit Facility, Remaining Borrowing Capacity	583.2
Line of Credit Facility, Maximum Borrowing Capacity	$ 476.9
Debt Instrument, Basis Spread on Variable Rate	1.75%
Debt Instrument, Interest Rate, Effective Percentage	6.90%
Line of Credit Facility, Interest Rate at Period End	0.25%
Corporate Segment [Member] | Letter of Credit [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	$ 16.8
TILC [Member] | Railcar Leasing and Management Services Group [Member] | Secured Debt [Member] | TRL-2023 Term Loan
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	300.1
TILC [Member] | Railcar Leasing and Management Services Group [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | TILC Warehouse Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	1,000.0
Proceeds from Lines of Credit	207.4
Repayments of Lines of Credit	383.7
Line of Credit Facility, Remaining Borrowing Capacity	454.5
Line of Credit Facility, Maximum Borrowing Capacity	$ 129.9
Debt Instrument, Basis Spread on Variable Rate	1.85%
Debt Instrument, Interest Rate, Effective Percentage	7.12%
Wholly-owned subsidiaries | Railcar Leasing and Management Services Group [Member] | Line of Credit [Member] | TRL-2023 Term Loan
Debt Instrument [Line Items]
Payments of Debt Issuance Costs	$ 2.2
Proceeds from Lines of Credit	$ 340.0
Debt Instrument, Basis Spread on Variable Rate	1.80%
Debt Instrument, Interest Rate, Effective Percentage	6.96%
Minimum | Corporate Segment [Member] | Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End	0.175%
Maximum | Corporate Segment [Member] | Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End	0.40%