Note 10. Employee Retirement Plans Employee Retirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension plan settlement	$ 0.0	$ (151.5)	$ 0.0
Assets for Plan Benefits, Defined Benefit Plan	16.6
Defined Contribution Plan, Employer Discretionary Contribution Amount	19.4
Final annuity contract true-up, net of administrative expenses	2.5
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement	6.4
Transfers	(10.9)	0.0
Defined Benefit Plan, Excise Tax from Reversion of Surplus Plan Assets	3.2
Reversion of excess plan assets	(16.0)	0.0
Trinity Industries, Inc. Consolidated Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	0.6	$ 23.6
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 10.9