Earnings Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net Income Per Common Share (Textual) [Abstract]
Total weighted average restricted shares and antidilutive stock options, number of shares	3.6	3.3	3.4	3.2
Computation of basic and diluted net income attributable to Trinity Industries, Inc
Net income from continuing operations	$ 89.2	$ 66.1	$ 161.4	$ 118.5
Less: net income (loss) from continuing operations attributable to noncontrolling interest	4.2	(0.3)	3.9	(0.9)
Net income from continuing operations attributable to Trinity Industries, Inc.	85.0	66.4	157.5	119.4
Unvested restricted share participation	(2.7)	(2.3)	(5.0)	(3.7)
Net income from continuing operations attributable to Trinity Industries, Inc. - basic	82.3	64.1	152.5	115.7
Net income from continuing operations attributable to Trinity Industries, Inc. - basic, Average Shares	77.0	77.7	77.0	77.7
Net income from continuing operations attributable to Trinity Industries, Inc. - basic, EPS	$ 1.07	$ 0.82	$ 1.98	$ 1.49
Effect of dilutive securities:
Stock options, Income (Loss)	0	0	0	0
Stock options, Average Shares	0.1	0.2	0.1	0.2
Net income from continuing operations attributable to Trinity Industries, Inc. - diluted	82.3	64.1	152.5	115.7
Net income from continuing operations attributable to Trinity Industries, Inc. - diluted, Average Shares	77.1	77.9	77.1	77.9
Net income from continuing operations attributable to Trinity Industries, Inc. - diluted, EPS	$ 1.07	$ 0.82	$ 1.98	$ 1.49
Net income (loss) from discontinued operations, net of taxes	(1.0)	1.4	5.6	1.3
Unvested restricted share participation	0	0	(0.2)	(0.3)
Net income (loss) from discontinued operations, net of taxes - basic	(1.0)	1.4	5.4	1.0
Net income (loss) from discontinued operations, net of taxes - basic, EPS	$ (0.01)	$ 0.02	$ 0.07	$ 0.01
Net income (loss) from discontinued operations, net of taxes - diluted	$ (1.0)	$ 1.4	$ 5.4	$ 1.0
Net income (loss) from discontinued operations, net of taxes - diluted, EPS	$ (0.01)	$ 0.02	$ 0.07	$ 0.01