Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 364.7	$ 826.0	$ 709.3
Derivative financial instruments:
Unrealized losses arising during the period, net of tax benefit of $-, $0.2, and $0.6	(0.3)	(0.7)	(1.2)
Reclassification adjustments for losses included in net income, net of tax benefit of $0.7, $3.4, and $8.4	4.6	9.0	16.0
Currency translation adjustment	0.8	(6.0)	(2.0)
Defined benefit plans:
Unrealized losses arising during the period, net of tax benefit of $2.0, $3.4, and $26.7	(3.3)	(6.0)	(45.1)
Amortization of net actuarial losses, net of tax benefit of $1.9, $1.8, and $0.8	3.2	3.2	1.3
Total other comprehensive income (loss)	5.0	(0.5)	(31.0)
Comprehensive income	369.7	825.5	678.3
Less: comprehensive income attributable to noncontrolling interest	24.2	32.5	34.1
Comprehensive income attributable to Trinity Industries, Inc.	$ 345.5	$ 793.0	$ 644.2