Cover Page - shares	6 Months Ended
	Jun. 30, 2023	Jul. 24, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-38534
Entity Registrant Name	Amerant Bancorp Inc.
Entity Incorporation, State or Country Code	FL
Entity Tax Identification Number	65-0032379
Entity Address, Address Line One	220 Alhambra Circle
Entity Address, City or Town	Coral Gables,
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33134
City Area Code	(305)
Local Phone Number	460-4728
Title of 12(b) Security	Class A Common Stock
Trading Symbol	AMTB
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		33,696,505
Entity Central Index Key	0001734342
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false