Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income (loss)	$ 72.9	$ 181.8	$ (226.2)
Unrealized gains (losses) arising during the period, net of tax benefit (expense) of $(9.2), $(2.8), and $5.9	29.3	9.2	(19.4)
Reclassification adjustments for losses included in net income (loss), net of tax benefit of $0.8, $1.2, and $3.5	3.5	5.4	12.9
Settlement of pension plan, net of tax benefit of $—, $—, and $34.9	0.0	0.0	116.6
Unrealized gains arising during the period, net of tax expense of $0.5, $0.1, and $2.7	2.1	0.3	7.7
Amortization of prior service cost, net of tax benefit of $—, $—, and $0.3	0.0	0.0	0.9
Amortization of net actuarial losses, net of tax benefit of $0.1, $0.1, and $1.3	0.2	0.2	4.7
Reclassification adjustments for losses included in discontinued operations, net of tax benefit of $—, $—, and $—	(1.3)	0.0	0.0
Other comprehensive income (loss):	36.4	15.1	123.4
Comprehensive income (loss)	109.3	196.9	(102.8)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	12.5	1.0	(77.7)
Comprehensive income (loss) attributable to Trinity Industries, Inc.	$ 96.8	$ 195.9	$ (25.1)