Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income	$ 709.3	$ 392.4	$ 253.7
Derivative financial instruments:
Unrealized gains/(losses) arising during the period, net of tax expense/ (benefit) of $(0.6), $0.8, and $4.2	(1.2)	0.8	7.2
Unrealized gains (losses) arising during the period, tax expense (benefit)	(0.6)	0.8	4.2
Reclassification adjustments for losses included in net income, net of tax benefit of $8.4, $8.7, and $3.2	16.0	18.1	5.8
Reclassification adjustments for losses included in net income, tax benefit	8.4	8.7	3.2
Currency translation adjustment	(2.0)	0	0.6
Defined benefit plans:
Unrealized gains/(losses) arising during the period, net of tax expense/ (benefit) of $(26.7), $31.0, and $(17.8)	(45.1)	52.7	(30.3)
Unrealized gains (losses) arising during the period, tax expense (benefit)	(26.7)	31.0	(17.8)
Amortization of net actuarial losses, net of tax benefit of $0.8, $1.9, and $1.1	1.3	3.1	2.2
Amortization of net actuarial losses, tax benefit	0.8	1.9	1.1
Total other comprehensive income (loss)	(31.0)	74.7	(14.5)
Comprehensive income	678.3	467.1	239.2
Less: comprehensive income attributable to noncontrolling interest	34.1	21.1	0.1
Comprehensive income attributable to Trinity Industries, Inc.	$ 644.2	$ 446.0	$ 239.1