| Document and Entity Information | Oct. 31, 2019 |
| Document And Entity Information [Line Items] | |
| Current Fiscal Year End Date | --12-31 |
| Amendment Flag | false |
| Entity Central Index Key | 0001660734 |
| Document Type | 8-K |
| Document Period End Date | Oct. 31, 2019 |
| Entity Registrant Name | TRITON INTERNATIONAL LIMITED |
| Entity Incorporation, State or Country Code | D0 |
| Entity File Number | 001-37827 |
| Entity Tax Identification Number | 98-1276572 |
| Entity Address, Address Line One | Victoria Place |
| Entity Address, Address Line Two | 5th Floor, 31 Victoria Street |
| Entity Address, City or Town | Hamilton |
| Entity Address, Postal Zip Code | HM 10 |
| Entity Address, Country | BM |
| City Area Code | 441 |
| Local Phone Number | 294-8033 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common shares, $0.01 par value per share | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | Common shares, $0.01 par value per share |
| Trading Symbol | TRTN |
| Security Exchange Name | NYSE |
| 8.50% Series A Cumulative Redeemable Perpetual Preference Shares | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | 8.50% Series A Cumulative Redeemable Perpetual Preference Shares |
| Trading Symbol | TRTN PR A |
| Security Exchange Name | NYSE |
| 8.00% Series B Cumulative Redeemable Perpetual Preference Shares | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | 8.00% Series B Cumulative Redeemable Perpetual Preference Shares |
| Trading Symbol | TRTN PR B |
| Security Exchange Name | NYSE |
