Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Total revenues	$ 1,103.8	$ 1,111.7	$ 1,184.9	$ 1,187.9	$ 1,547.0	$ 1,542.2	$ 1,676.8	$ 1,626.7	$ 4,588.3	$ 6,392.7	$ 6,170.0
Cost of revenues:
Total cost of revenues	841.2	827.3	897.7	889.9	1,116.1	1,109.4	1,219.6	1,211.1	3,456.1	4,656.2	4,619.8
Selling, engineering, and administrative expenses	101.9	102.3	106.7	96.5	137.1	126.6	114.4	98.3	407.4	476.4	403.6
Gains on disposition of property	2.9	1.5	11.1	1.9	64.2	58.7	40.1	15.8	17.4	178.8	104.4
Operating profit	163.6	183.6	191.6	203.4	358.0	364.9	382.9	333.1	742.2	1,438.9	1,251.0
Net income	74.2	89.6	98.8	102.1	204.0	212.2	220.8	189.0	364.7	826.0	709.3
Net income attributable to Trinity Industries, Inc.	$ 67.6	$ 84.2	$ 94.6	$ 97.2	$ 200.0	$ 204.3	$ 212.0	$ 180.2	$ 343.6	$ 796.5	$ 678.2
Net income attributable to Trinity Industries, Inc. per common share:
Basic (in dollars per share)	$ 0.44	$ 0.55	$ 0.62	$ 0.64	$ 1.30	$ 1.32	$ 1.36	$ 1.15	$ 2.25	$ 5.14	$ 4.35
Diluted (in dollars per share)	$ 0.44	$ 0.55	$ 0.62	$ 0.64	$ 1.30	$ 1.31	$ 1.33	$ 1.13	$ 2.25	$ 5.08	$ 4.19
Manufacturing
Revenues:
Total revenues	$ 926.0	$ 938.5	$ 888.8	$ 1,010.1	$ 1,177.6	$ 1,295.6	$ 1,445.4	$ 1,382.5	$ 3,763.4	$ 5,301.1	$ 5,063.6
Cost of revenues:
Total cost of revenues	761.2	745.4	719.1	793.9	881.6	976.0	1,101.8	1,084.5	3,019.6	4,043.9	3,975.1
Selling, engineering, and administrative expenses									231.0	271.4	235.0
Leasing
Revenues:
Total revenues	177.8	173.2	296.1	177.8	369.4	246.6	231.4	244.2	824.9	1,091.6	1,106.4
Cost of revenues:
Total cost of revenues	$ 80.0	$ 81.9	$ 178.6	$ 96.0	$ 234.5	$ 133.4	$ 117.8	$ 126.6	436.5	612.3	644.7
Selling, engineering, and administrative expenses									$ 45.4	$ 52.4	$ 49.6