Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 162.3	$ 30.1
Derivative financial instruments:
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(25.6)	(5.5)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	1.0	0.9
Defined benefit plans:
Amortization of net actuarial losses, net of tax benefit	1.2	0.8
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax	0.2	0.0
Other comprehensive income	(23.2)	(3.8)
Comprehensive income	139.1	26.3
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0.9	(0.2)
Comprehensive income attributable to Trinity Industries, Inc.	$ 138.2	$ 26.5