Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Statement of Comprehensive Income [Abstract]
Net income	$ 24.8	$ 27.1
Other comprehensive income (loss):
Unrealized gains (losses) arising during the period, net of tax benefit (expense) of $(2.3) and $0.6	7.4	(2.0)
Reclassification adjustments for (gains) losses included in net income, net of tax benefit (expense) of $(0.7) and $0.5	(2.2)	2.1
Other Comprehensive Income (Loss), Net of Tax, Total	5.2	0.1
Comprehensive income	30.0	27.2
Less: comprehensive income attributable to noncontrolling interest	0.6	5.1
Comprehensive income attributable to Trinity Industries, Inc.	$ 29.4	$ 22.1