| Cover | Nov. 09, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 9, 2021 |
| Entity File Number | 001-36135 |
| Entity Registrant Name | Brookfield DTLA Fund Office Trust Investor Inc. |
| Entity Central Index Key | 0001575311 |
| Entity Tax Identification Number | 04-2616226 |
| Entity Incorporation, State or Country Code | MD |
| Entity Address, Address Line One | 250 Vesey Street |
| Entity Address, Address Line Two | 15th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10281 |
| City Area Code | 212 |
| Local Phone Number | 417-7000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | 7.625% Series A Cumulative Redeemable Preferred Stock, $0.01 par value per share |
| Trading Symbol | DTLA-P |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
