Note 5. Partially Owned Leasing Subsidiaries (Details)	3 Months Ended								12 Months Ended			18 Months Ended
	Dec. 31, 2022 USD ($) board_member	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2022 USD ($) board_member subsidiary	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2022 USD ($) board_member	Aug. 18, 2021
Noncontrolling Interest [Line Items]
Gains on dispositions of property:	$ 60,200,000	$ 39,400,000	$ 27,800,000	$ 25,300,000	$ 13,000,000.0	$ 41,600,000	$ 12,100,000	$ 11,500,000	$ 152,700,000	$ 78,200,000	$ 20,000,000.0
Revenues	$ 591,200,000	$ 496,600,000	$ 416,800,000	$ 472,700,000	$ 472,200,000	$ 419,800,000	$ 293,300,000	$ 330,700,000	$ 1,977,300,000	$ 1,516,000,000	$ 1,749,700,000
Signal Rail Holdings LLC
Noncontrolling Interest [Line Items]
Equity Method Investment, JV Majority Ownership Percentage													90.00%
Equity Method Investment, Ownership Percentage	12.90%								12.90%			12.90%	10.00%
Proceeds from Equity Method Investment, Distribution									$ 13,500,000
Equity Method Investments	$ 20,200,000								20,200,000			$ 20,200,000
Signal Rail Holdings LLC
Noncontrolling Interest [Line Items]
Equity Method Investment, Aggregate Future Estimated Investment of Railcars	1,000,000,000								1,000,000,000			1,000,000,000
Proceeds from Sales of Business, Affiliate and Productive Assets									254,100,000			579,200,000
Gains on dispositions of property:									25,100,000
Revenues									2,500,000
Partially-Owned Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Parent Company Guarantees	0								0			0
Railcar Leasing and Management Services Group [Member] | Partially-Owned Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Carrying Value of Investment In Partially-Owned Consolidated Subsidiary	$ 136,100,000								$ 136,100,000			$ 136,100,000
Noncontrolling Interest, Ownership Percentage by Parent	38.00%								38.00%			38.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	62.00%								62.00%			62.00%
Railcar Leasing and Management Services Group [Member] | Partially-Owned Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Number of Subsidiaries | subsidiary									2
Number of Board Members | board_member	7								7			7
Number of Board Members of Subsidiary, Designated by Parent | board_member	2								2			2