Cover Page - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Aug. 02, 2021
Document Information [Line Items]
Document Transition Report		false
Entity Address, Address Line One		14817 Oak Lane
Entity Address, City or Town		Miami Lakes
Entity Address, State or Province		FL
Entity Address, Postal Zip Code		33016
Entity Registrant Name		BankUnited, Inc.
Entity Central Index Key		0001504008
Current Fiscal Year End Date	--12-31
Entity Filer Category		Large Accelerated Filer
Document Type		10-Q
Document Period End Date		Jun. 30, 2021
Document Fiscal Year Focus		2021
Entity File Number		001-35039
Document Fiscal Period Focus		Q2
Document Annual Report		true
Amendment Flag		false
Entity Common Stock Shares Outstanding			92,820,882
Entity Interactive Data Current		Yes
Entity Shell Company		false
Entity Shell Company		DE
Entity Tax Identification Number		27-0162450
City Area Code		305
Local Phone Number		569-2000
Entity Small Business		false
Entity Emerging Growth Company		false
Entity Current Reporting Status		Yes
NEW YORK STOCK EXCHANGE, INC. [Member]
Document Information [Line Items]
Security Exchange Name		NYSE
Trading Symbol		BKU
Title of 12(b) Security		Common Stock, $0.01 Par Value