Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 102.1	$ 189.0
Derivative financial instruments:
Unrealized losses arising during the period, net of tax benefit of $0.2 and $0.2	(0.4)	(0.3)
Reclassification adjustments for losses included in net income, net of tax benefit of $0.4 and $2.1	1.0	3.8
Currency translation adjustment	1.5	(3.8)
Defined benefit plans:
Amortization of net actuarial losses, net of tax benefit of $0.5 and $0.5	0.8	0.8
Other comprehensive income	2.9	0.5
Comprehensive income	105.0	189.5
Less: comprehensive income attributable to noncontrolling interest	5.4	9.4
Comprehensive income attributable to Trinity Industries, Inc.	$ 99.6	$ 180.1