Note 5. Partially Owned Leasing Subsidiaries (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2021 USD ($) board_member	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) board_member subsidiary	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Noncontrolling Interest [Line Items]
Revenues	$ 472,200,000	$ 419,800,000	$ 293,300,000	$ 330,700,000	$ 359,700,000	$ 396,800,000	$ 439,900,000	$ 553,300,000	$ 1,516,000,000	$ 1,749,700,000	$ 2,752,400,000
Gains on dispositions of property:	$ 13,000,000.0	$ 41,600,000	$ 12,100,000	$ 11,500,000	$ 100,000	$ 3,700,000	$ 6,600,000	$ 9,600,000	$ 78,200,000	20,000,000.0	54,400,000
Signal Rail Holdings LLC
Noncontrolling Interest [Line Items]
Equity Method Investment, JV Majority Ownership Percentage	90.00%								90.00%
Equity Method Investment, Ownership Percentage	10.00%								10.00%
Equity Method Investment, Aggregate Future Estimated Investment of Railcars	$ 1,000,000,000								$ 1,000,000,000
Aggregate Sales Price of Equipment Sold									325,100,000
Proceeds from Sale of Property, Plant, and Equipment									318,700,000
Revenues									2,900,000
Proceeds from Equity Method Investment, Distribution									6,400,000
Gains on dispositions of property:									32,900,000
Partially-Owned Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Parent Company Guarantees	0								0
Railcar Leasing and Management Services Group [Member]
Noncontrolling Interest [Line Items]
Revenues									735,300,000	$ 802,300,000	$ 1,117,200,000
Railcar Leasing and Management Services Group [Member] | Partially-Owned Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Carrying Value of Investment In Partially-Owned Consolidated Subsidiary	$ 141,400,000								$ 141,400,000
Noncontrolling Interest, Ownership Percentage by Parent	38.00%								38.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	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
Number of Board Members of Subsidiary, Designated by Parent | board_member	2								2