Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Total weighted average restricted shares and antidilutive stock options (in shares)	6.8	7.4	7.0
Computation of basic and diluted net income attributable to Trinity Industries, Inc
Net income from continuing operations, Income (Loss)	$ 826.0	$ 709.3	$ 386.1
Net income attributable to noncontrolling interest, Income (Loss)	29.5	31.1	16.9
Net income from continuing operations attributable to Trinity Industries, Inc., Income (Loss)	796.5	678.2	369.2
Income (loss) from discontinued operations, net of provision (benefit) for income taxes, Income (Loss)	$ 0.0	$ 0.0	$ 6.3
Net income - basic, Average Shares (in shares)	150.2	151.0	152.8
Net income from continuing operations attributable to Trinity Industries, Inc. – basic, EPS (in dollars per share)	$ 5.14	$ 4.35	$ 2.34
Net income from discontinued operations, net of taxes – basic, EPS (in dollars per share)	$ 0.00	$ 0.00	$ 0.04
Effect of dilutive securities:
Net income attributable to Trinity Industries, Inc. - diluted, Average Shares (in shares)	152.2	156.7	152.9
Net income from continuing operations attributable to Trinity Industries, Inc. – diluted, EPS (in dollars per share)	$ 5.08	$ 4.19	$ 2.34
Net income from discontinued operations, net of taxes – diluted, EPS (in dollars per share)	$ 0.00	$ 0.00	$ 0.04
Continuing operations
Computation of basic and diluted net income attributable to Trinity Industries, Inc
Unvested restricted share participation, Income (Loss)	$ (24.1)	$ (22.1)	$ (12.0)
Net income - basic, Income (Loss)	$ 772.4	$ 656.1	$ 357.2
Net income - basic, Average Shares (in shares)	150.2	151.0	152.8
Effect of dilutive securities:
Stock options, Income (Loss)	$ 0.0	$ 0.0	$ 0.0
Stock options, Average Shares (in shares)	0.0	0.1	0.1
Convertible subordinated notes, Income (Loss)	$ 0.3	$ 0.7	$ 0.0
Convertible subordinated notes, Average Shares (in shares)	2.0	5.6	0.0
Net income from attributable to Trinity Industries, Inc. - diluted, Income (Loss)	$ 772.7	$ 656.8	$ 357.2
Net income attributable to Trinity Industries, Inc. - diluted, Average Shares (in shares)	152.2	156.7	152.9
Discontinued operations
Computation of basic and diluted net income attributable to Trinity Industries, Inc
Unvested restricted share participation, Income (Loss)	$ 0.0	$ 0.0	$ (0.2)
Net income - basic, Income (Loss)	$ 0.0	$ 0.0	$ 6.1
Net income - basic, Average Shares (in shares)	150.2	151.0	152.8
Effect of dilutive securities:
Stock options, Income (Loss)	$ 0.0	$ 0.0	$ 0.0
Stock options, Average Shares (in shares)	0.0	0.1	0.1
Convertible subordinated notes, Income (Loss)	$ 0.0	$ 0.0	$ 0.0
Convertible subordinated notes, Average Shares (in shares)	2.0	5.6	0.0
Net income from attributable to Trinity Industries, Inc. - diluted, Income (Loss)	$ 0.0	$ 0.0	$ 6.1
Net income attributable to Trinity Industries, Inc. - diluted, Average Shares (in shares)	152.2	156.7	152.9