| Document and Entity Information Document - $ / shares | Feb. 19, 2020 | Mar. 31, 2020 |
| Document Information [Line Items] | ||
| Entity Address, Address Line One | 14817 Oak Lane, | |
| Entity Central Index Key | 0001504008 | |
| Entity Incorporation, State or Country Code | DE | |
| Document Type | 8-K | |
| Document Period End Date | Feb. 19, 2020 | |
| 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 | |
| Common Stock, Dividends, Per Share, Declared | $ 0.23 | |
| 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 |
