Note 10. Employee Retirement Plans Accumulated Benefit Obligations and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Accumulated Benefit Obligations	$ 14.5	$ 15.5
Defined Benefit Plan, Benefit Obligation	14.5	15.5	$ 557.9
Service cost	0.0	0.0	0.1
Interest	0.4	14.8	19.7
Benefits paid	(1.0)	(23.0)
Actuarial (gain) loss	(0.4)	18.0
Settlements	0.0	(552.2)
Defined Benefit Plan, Plan Assets, Amount	0.6	23.6	$ 548.5
Actual return on assets	0.0	49.3
Employer contributions	1.0	1.0
Benefits paid	(1.0)	(23.0)
Settlements	0.0	(552.2)
Transfers	(10.9)	0.0
Final annuity contract true-up, net of administrative expenses	3.9	0.0
Reversion of excess plan assets	(16.0)	0.0
Defined Benefit Plan, Plan Assets, Category [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	16.6
Trinity Industries, Inc. Consolidated Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Category [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	0.6	23.6
Liability, Defined Benefit Plan	0.0	0.0
Defined Benefit Plan, Funded (Unfunded) Status of Plan	0.6	23.6
Supplemental Executive Retirement Plan (SERP) [Member]
Defined Benefit Plan, Plan Assets, Category [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	0.0	0.0
Liability, Defined Benefit Plan	(14.5)	(15.5)
Defined Benefit Plan, Funded (Unfunded) Status of Plan	$ (14.5)	$ (15.5)