Financial Statements for Guarantors of the Senior Notes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Income Statements, Captions [Line Items]
Revenues	$ 1,184.9	$ 1,676.8	$ 2,372.8	$ 3,303.5
Cost of revenues	897.7	1,219.6	1,787.6	2,430.7
Selling, engineering, and administrative expenses	106.7	114.4	203.2	212.7
Gains/(losses) on dispositions of property	11.1	40.1	13.0	55.9
Cost of revenues and operating costs	993.3	1,293.9	1,977.8	2,587.5
Total operating profit	191.6	382.9	395.0	716.0
Other (income) expense	39.4	49.4	83.3	98.1
Equity in earnings of subsidiaries, net of taxes	0.0	0.0	0.0	0.0
Income before income taxes	152.2	333.5	311.7	617.9
Provision (benefit) for income taxes	53.4	112.7	110.8	208.1
Net income	98.8	220.8	200.9	409.8
Net income attributable to noncontrolling interest	4.2	8.8	9.1	17.6
Net income attributable to Trinity Industries, Inc.	94.6	212.0	191.8	392.2
Other comprehensive income (loss)	2.0	4.6	4.9	5.1
Comprehensive income	100.8	225.4	205.8	414.9
Comprehensive income attributable to noncontrolling interest	4.9	9.7	10.3	19.1
Comprehensive income attributable to Trinity Industries, Inc.	95.9	215.7	195.5	395.8
Reportable legal entities | Parent
Condensed Income Statements, Captions [Line Items]
Revenues	0.0	0.0	0.0	0.0
Cost of revenues	(1.3)	(1.1)	(3.5)	(1.9)
Selling, engineering, and administrative expenses	33.2	30.8	56.8	56.2
Gains/(losses) on dispositions of property	(0.7)	1.4	(0.9)	1.6
Cost of revenues and operating costs	32.6	28.3	54.2	52.7
Total operating profit	(32.6)	(28.3)	(54.2)	(52.7)
Other (income) expense	(1.2)	2.7	(0.1)	7.1
Equity in earnings of subsidiaries, net of taxes	106.0	246.3	228.1	443.2
Income before income taxes	74.6	215.3	174.0	383.4
Provision (benefit) for income taxes	(20.0)	3.3	(17.8)	(8.8)
Net income	94.6	212.0	191.8	392.2
Net income attributable to noncontrolling interest	0.0	0.0	0.0	0.0
Net income attributable to Trinity Industries, Inc.	94.6	212.0	191.8	392.2
Other comprehensive income (loss)	0.9	2.0	3.0	1.0
Comprehensive income	95.5	214.0	194.8	393.2
Comprehensive income attributable to noncontrolling interest	0.0	0.0	0.0	0.0
Comprehensive income attributable to Trinity Industries, Inc.	95.5	214.0	194.8	393.2
Reportable legal entities | Combined Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues	750.1	1,215.0	1,500.0	2,400.0
Cost of revenues	605.8	945.1	1,217.1	1,889.2
Selling, engineering, and administrative expenses	33.2	38.1	65.1	71.1
Gains/(losses) on dispositions of property	10.5	7.9	10.3	7.8
Cost of revenues and operating costs	628.5	975.3	1,271.9	1,952.5
Total operating profit	121.6	239.7	228.1	447.5
Other (income) expense	8.7	9.1	17.3	16.0
Equity in earnings of subsidiaries, net of taxes	16.0	66.8	42.6	124.6
Income before income taxes	128.9	297.4	253.4	556.1
Provision (benefit) for income taxes	48.6	92.2	85.6	180.1
Net income	80.3	205.2	167.8	376.0
Net income attributable to noncontrolling interest	0.0	0.0	0.0	0.0
Net income attributable to Trinity Industries, Inc.	80.3	205.2	167.8	376.0
Other comprehensive income (loss)	0.0	0.0	0.0	(0.5)
Comprehensive income	80.3	205.2	167.8	375.5
Comprehensive income attributable to noncontrolling interest	0.0	0.0	0.0	0.0
Comprehensive income attributable to Trinity Industries, Inc.	80.3	205.2	167.8	375.5
Reportable legal entities | Combined Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues	620.6	701.0	1,261.5	1,371.4
Cost of revenues	483.7	522.0	972.3	1,021.3
Selling, engineering, and administrative expenses	40.3	45.5	81.3	85.4
Gains/(losses) on dispositions of property	1.3	30.8	3.6	46.5
Cost of revenues and operating costs	522.7	536.7	1,050.0	1,060.2
Total operating profit	97.9	164.3	211.5	311.2
Other (income) expense	31.9	37.6	66.1	75.0
Equity in earnings of subsidiaries, net of taxes	0.0	0.0	0.0	0.0
Income before income taxes	66.0	126.7	145.4	236.2
Provision (benefit) for income taxes	23.1	14.6	39.6	33.2
Net income	42.9	112.1	105.8	203.0
Net income attributable to noncontrolling interest	0.0	0.0	0.0	0.0
Net income attributable to Trinity Industries, Inc.	42.9	112.1	105.8	203.0
Other comprehensive income (loss)	1.1	2.6	1.9	4.6
Comprehensive income	44.0	114.7	107.7	207.6
Comprehensive income attributable to noncontrolling interest	0.0	0.0	0.0	0.0
Comprehensive income attributable to Trinity Industries, Inc.	44.0	114.7	107.7	207.6
Eliminations
Condensed Income Statements, Captions [Line Items]
Revenues	(185.8)	(239.2)	(388.7)	(467.9)
Cost of revenues	(190.5)	(246.4)	(398.3)	(477.9)
Selling, engineering, and administrative expenses	0.0	0.0	0.0	0.0
Gains/(losses) on dispositions of property	0.0	0.0	0.0	0.0
Cost of revenues and operating costs	(190.5)	(246.4)	(398.3)	(477.9)
Total operating profit	4.7	7.2	9.6	10.0
Other (income) expense	0.0	0.0	0.0	0.0
Equity in earnings of subsidiaries, net of taxes	(122.0)	(313.1)	(270.7)	(567.8)
Income before income taxes	(117.3)	(305.9)	(261.1)	(557.8)
Provision (benefit) for income taxes	1.7	2.6	3.4	3.6
Net income	(119.0)	(308.5)	(264.5)	(561.4)
Net income attributable to noncontrolling interest	4.2	8.8	9.1	17.6
Net income attributable to Trinity Industries, Inc.	(123.2)	(317.3)	(273.6)	(579.0)
Other comprehensive income (loss)	0.0	0.0	0.0	0.0
Comprehensive income	(119.0)	(308.5)	(264.5)	(561.4)
Comprehensive income attributable to noncontrolling interest	4.9	9.7	10.3	19.1
Comprehensive income attributable to Trinity Industries, Inc.	$ (123.9)	$ (318.2)	$ (274.8)	$ (580.5)