Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 51.7	$ 102.1
Derivative financial instruments:
Unrealized losses arising during the period, net of tax benefit of $- and $0.2	0.0	(0.4)
Reclassification adjustments for losses included in net income, net of tax benefit of $0.3 and $0.4	1.0	1.0
Currency translation adjustment	0.3	1.5
Defined benefit plans:
Amortization of net actuarial losses, net of tax benefit of $0.4 and $0.5	0.8	0.8
Other comprehensive income	2.1	2.9
Comprehensive income	53.8	105.0
Less: comprehensive income attributable to noncontrolling interest	6.5	5.4
Comprehensive income attributable to Trinity Industries, Inc.	$ 47.3	$ 99.6