Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Statement of Comprehensive Income [Abstract]
Net income	$ 27.1	$ 27.4
Other comprehensive income (loss):
Unrealized gains (losses) arising during the period, net of tax benefit (expense) of $0.6 and $(3.4)	(2.0)	11.4
Reclassification adjustments for (gains) losses included in net income, net of tax benefit (expense) of $0.5 and $(1.2)	2.1	(3.9)
Other Comprehensive Income (Loss), Net of Tax, Total	0.1	7.5
Comprehensive income	27.2	34.9
Less: comprehensive income attributable to noncontrolling interest	5.1	3.8
Comprehensive income attributable to Trinity Industries, Inc.	$ 22.1	$ 31.1