Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 52.3	$ 25.6
Unrealized loss on derivative financial instruments:
Unrealized gains arising during the period	2.7	14.3
Reclassification adjustments for losses included in net income	2.3	0.8
Funded status of pension liability - amortization of actuarial loss	0.9
Other comprehensive income, before tax	5.9	15.1
Income tax expense related to components of other comprehensive income	2.4	5.4
Other comprehensive income, net of tax	3.5	9.7
Comprehensive income	55.8	35.3
Less: comprehensive income (loss) attributable to noncontrolling interest	(0.1)	3.7
Comprehensive income attributable to Trinity Industries, Inc.	$ 55.9	$ 31.6