| Document and Entity Information Document | Oct. 21, 2021 |
| Document Information [Line Items] | |
| Entity Address, Address Line One | 14817 Oak Lane, |
| Entity Incorporation, State or Country Code | DE |
| Document Type | 8-K |
| Document Period End Date | Oct. 21, 2021 |
| Entity Registrant Name | BankUnited, Inc. |
| City Area Code | 305 |
| Local Phone Number | 569-2000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity File Number | 001-35039 |
| Entity Tax Identification Number | 27-0162450 |
| Entity Address, City or Town | Miami Lakes, |
| Entity Address, State or Province | FL |
| Entity Address, Postal Zip Code | 33016 |
| Amendment Flag | false |
| Entity Central Index Key | 0001504008 |
| NEW YORK STOCK EXCHANGE, INC. [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock, $0.01 Par Value |
| Trading Symbol | BKU |
| Security Exchange Name | NYSE |
