Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 98.8	$ 220.8	$ 200.9	$ 409.8
Derivative financial instruments:
Unrealized losses arising during the period, net of tax benefit of $-, $-, $0.2, and $(0.2)	(0.3)	0.0	(0.7)	(0.3)
Reclassification adjustments for losses included in net income, net of tax benefit of $0.1, $1.0, $0.5, and $3.1	1.2	2.6	2.2	6.4
Currency translation adjustment	0.3	1.2	1.8	(2.6)
Defined benefit plans:
Amortization of net actuarial losses, net of tax benefit of $0.5, $0.5, $1.0, and $1.0	0.8	0.8	1.6	1.6
Other comprehensive income	2.0	4.6	4.9	5.1
Comprehensive income	100.8	225.4	205.8	414.9
Less: comprehensive income attributable to noncontrolling interest	4.9	9.7	10.3	19.1
Comprehensive income attributable to Trinity Industries, Inc.	$ 95.9	$ 215.7	$ 195.5	$ 395.8