Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues [Abstract]
Revenues	$ 615.2	$ 604.8
Cost of revenues:
Total cost of revenues	482.0	463.4
Selling, engineering, and administrative expenses:
Selling, engineering, and administrative expenses	64.3	59.6
Gains (losses) on dispositions of property:
Net gains on railcar lease fleet sales owned more than one year at the time of sale	8.7	7.9
Other	0.9	2.1
Total gains (losses) on disposition of property	9.6	10.0
Restructuring Charges	5.5	0.0
Total operating profit	73.0	91.8
Other (income) expense:
Interest income	(2.4)	(1.3)
Interest expense	61.3	52.7
Other Nonoperating Income (Expense)	(0.8)	0.3
Other Nonoperating Expense	58.1	51.7
Income from continuing operations before income taxes	14.9	40.1
Current Income Tax Expense (Benefit)	(372.8)	(0.8)
Provision for deferred income taxes	225.2	9.7
Provision (benefit) for income taxes	(147.6)	8.9
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	162.5	31.2
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(0.2)	(1.1)
Net income	162.3	30.1
Net income (loss) attributable to noncontrolling interest	0.6	(0.5)
Net income attributable to Trinity Industries, Inc.	$ 161.7	$ 30.6
Basic earnings per common share:
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.36	$ 0.24
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0	(0.01)
Earnings Per Share, Basic	1.36	0.23
Income (Loss) from Continuing Operations, Per Diluted Share	1.33	0.24
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0	(0.01)
Earnings Per Share, Diluted	$ 1.33	$ 0.23
Weighted average number of shares outstanding:
Basic (in shares)	118.0	130.4
Diluted (in shares)	119.9	132.2
Manufacturing
Revenues [Abstract]
Revenues	$ 379.1	$ 404.6
Cost of revenues:
Total cost of revenues	343.4	351.6
Selling, engineering, and administrative expenses:
Selling, engineering, and administrative expenses	21.9	23.2
Leasing
Revenues [Abstract]
Revenues	236.1	200.2
Cost of revenues:
Total cost of revenues	138.6	111.8
Selling, engineering, and administrative expenses:
Selling, engineering, and administrative expenses	14.3	12.8
Other
Selling, engineering, and administrative expenses:
Selling, engineering, and administrative expenses	$ 28.1	$ 23.6