Note 16. Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2022		Sep. 30, 2022		Jun. 30, 2022		Mar. 31, 2022		Dec. 31, 2021		Sep. 30, 2021		Jun. 30, 2021		Mar. 31, 2021		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues	$ 591.2		$ 496.6		$ 416.8		$ 472.7		$ 472.2		$ 419.8		$ 293.3		$ 330.7		$ 1,977.3	$ 1,516.0	$ 1,749.7
Cost of revenues:	490.2		395.3		325.6		398.5		375.7		337.4		202.1		246.3		1,609.6	1,161.5	1,327.4
Selling, engineering, and administrative expenses:	47.7		48.0		45.0		44.7		42.9		45.8		46.2		44.7		185.4	179.6	189.6
Gains on dispositions of property:	60.2		39.4		27.8		25.3		13.0		41.6		12.1		11.5		152.7	78.2	20.0
Restructuring activities, net	0.0		0.0		1.0		0.0		(2.6)		(0.1)		(0.7)		(0.3)		1.0	(3.7)	10.9
Total operating profit (loss)	113.5		92.7		73.0		54.8		69.2		78.3		57.8		51.5		334.0	256.8	(154.6)
Other (income) expense	60.5		54.4		50.7		41.9		41.1		44.5		63.5		52.5		207.5	201.6	370.0
Income (loss) from continuing operations before income taxes	53.0		38.3		22.3		12.9		28.1		33.8		(5.7)		(1.0)		126.5	55.2	(524.6)
Provision (benefit) for income taxes:	10.2		8.6		5.8		3.0		6.5		8.3		(2.9)		4.0		27.6	15.9	(274.1)
Income (loss) from continuing operations	42.8		29.7		16.5		9.9		21.6		25.5		(2.8)		(5.0)		98.9	39.3	(250.5)
Income (loss) from discontinued operations, net of provision (benefit) for income taxes of $(1.1), $3.5, and $5.5	(6.6)		(3.4)		(3.4)		(6.9)		(13.2)		10.4		7.6		6.3		(20.3)	11.1	24.3
Gain (loss) on sale of discontinued operations, net of provision (benefit) for income taxes of $(1.4), $51.9, and $—	0.0		0.0		(4.6)		(1.1)		131.4		0.0		0.0		0.0		(5.7)	131.4	0.0
Net income (loss)	36.2		26.3		8.5		1.9		139.8		35.9		4.8		1.3		72.9	181.8	(226.2)
Net income (loss) attributable to noncontrolling interest	4.9		0.5		4.8		2.6		5.8		3.9		(7.9)		(2.0)		12.8	(0.2)	(78.9)
Net income (loss) attributable to Trinity Industries, Inc.	$ 31.3		$ 25.8		$ 3.7		$ (0.7)		$ 134.0		$ 32.0		$ 12.7		$ 3.3		$ 60.1	$ 182.0	$ (147.3)
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.47	[1]	$ 0.36	[1]	$ 0.14	[1]	$ 0.09	[1]	$ 0.16	[1]	$ 0.22	[1]	$ 0.05	[1]	$ (0.03)	[1]	$ 1.05	$ 0.39	$ (1.48)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	(0.08)	[1]	(0.04)	[1]	(0.10)	[1]	(0.10)	[1]	1.23	[1]	0.11	[1]	0.07	[1]	0.06	[1]	(0.32)	1.40	0.21
Earnings Per Share, Basic	0.39	[1]	0.32	[1]	0.04	[1]	(0.01)	[1]	1.39	[1]	0.33	[1]	0.12	[1]	0.03	[1]	0.73	1.79	(1.27)
Income (Loss) from Continuing Operations, Per Diluted Share	0.46	[1]	0.35	[1]	0.14	[1]	0.09	[1]	0.16	[1]	0.22	[1]	0.05	[1]	(0.03)	[1]	1.02	0.38	(1.48)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	(0.08)	[1]	(0.04)	[1]	(0.10)	[1]	(0.10)	[1]	1.21	[1]	0.11	[1]	0.07	[1]	0.06	[1]	(0.31)	1.37	0.21
Earnings Per Share, Diluted	$ 0.38	[1]	$ 0.31	[1]	$ 0.04	[1]	$ (0.01)	[1]	$ 1.37	[1]	$ 0.33	[1]	$ 0.12	[1]	$ 0.03	[1]	$ 0.71	$ 1.75	$ (1.27)
Manufacturing [Member]
Revenues	$ 394.0		$ 302.0		$ 221.7		$ 289.8		$ 291.2		$ 234.5		$ 108.3		$ 147.4		$ 1,207.5	$ 781.4	$ 948.2
Cost of revenues:	382.2		288.0		220.8		295.6		281.9		238.8		99.6		149.6		1,186.6	769.9	910.0
Selling, engineering, and administrative expenses:																	34.2	32.5	38.6
Leasing [Member]
Revenues	197.2		194.6		195.1		182.9		181.0		185.3		185.0		183.3		769.8	734.6	801.5
Cost of revenues:	$ 108.0		$ 107.3		$ 104.8		$ 102.9		$ 93.8		$ 98.6		$ 102.5		$ 96.7		423.0	391.6	417.4
Selling, engineering, and administrative expenses:																	$ 54.0	$ 50.6	$ 51.3

[1] The sum of the quarters may not necessarily be equal to the full year net income per common share amount.