Derivative Instruments and Fair Value Accounting Derivative Instruments (Details) - USD ($) $ in Millions		Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 1,304.0	$ 1,288.5	$ 1,275.5	$ 1,249.0	$ 1,250.4	$ 1,269.6
Designated as Hedging Instrument [Member] | Interest Rate Swap, Expired, 2018 Secured Railcar Equipment Notes [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 249.3
Derivative, Average Fixed Interest Rate	[1]	4.41%
Derivative Asset		$ 0.0
Designated as Hedging Instrument [Member] | Interest Rate Swap, Expired, Tribute Rail Secured Railcar Equipment Notes
Derivative [Line Items]
Derivative, Notional Amount		$ 256.0
Derivative, Average Fixed Interest Rate	[1]	2.86%
Derivative Asset		$ 0.0
Designated as Hedging Instrument [Member] | Interest Rate Cap [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 169.3
Derivative, Cap Interest Rate		3.00%
Derivative Asset		$ 0.0
Designated as Hedging Instrument [Member] | Interest Rate Swap, 2017 Promissory Notes
Derivative [Line Items]
Derivative, Notional Amount		$ 394.7
Derivative, Average Fixed Interest Rate	[1]	2.31%
Derivative Asset		$ 12.7
Designated as Hedging Instrument [Member] | Interest Rate Swap, TRL-2023 Term Loan
Derivative [Line Items]
Derivative, Notional Amount		$ 263.2
Derivative, Average Fixed Interest Rate	[1]	3.79%
Derivative Asset		$ 2.9
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, Expired, 2018 Secured Railcar Equipment Notes [Member]
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		0.2
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, Expired, Tribute Rail Secured Railcar Equipment Notes
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		0.3
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Designated as Hedging Instrument [Member] | Interest Rate Cap [Member]
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(0.1)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, 2017 Promissory Notes
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(12.3)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, TRL-2023 Term Loan
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(2.8)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, Expired, 2018 Secured Railcar Equipment Notes [Member]
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		0.0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, Expired, Tribute Rail Secured Railcar Equipment Notes
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		0.4
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] | Designated as Hedging Instrument [Member] | Interest Rate Cap [Member]
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		0.0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, 2017 Promissory Notes
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		0.0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap, TRL-2023 Term Loan
Derivative [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 0.0

[1] Weighted average fixed interest rate, except for the interest rate cap on the 2017 promissory notes