| Document and Entity Information Document | Jan. 04, 2021 |
| Cover [Abstract] | |
| Title of 12(b) Security | Common Stock |
| Document Type | 8-K |
| Document Period End Date | Jan. 4, 2021 |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-6903 |
| Entity Tax Identification Number | 75-0225040 |
| Entity Address, Address Line One | 14221 N. Dallas Parkway, Suite 1100 |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75254 |
| City Area Code | 214 |
| Local Phone Number | 631-4420 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Registrant Name | TRINITY INDUSTRIES INC |
| Entity Central Index Key | 0000099780 |
| Amendment Flag | false |
| Trading Symbol | TRN |
| Security Exchange Name | NYSE |
| Entity Addresses [Line Items] | |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Address Line One | 14221 N. Dallas Parkway, Suite 1100 |
| Entity Address, Postal Zip Code | 75254 |
| Former Address | |
| Cover [Abstract] | |
| Entity Address, Address Line One | 2525 N. Stemmons Freeway |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75207-2401 |
| Entity Addresses [Line Items] | |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Address Line One | 2525 N. Stemmons Freeway |
| Entity Address, Postal Zip Code | 75207-2401 |
