Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest income
Loans	$ 293,210	$ 216,097	$ 220,898
Investment securities	41,413	31,500	39,023
Interest earning deposits with banks	4,153	247	633
Total interest income	338,776	247,844	260,554
Interest expense
Interest bearing demand deposits	15,118	591	439
Savings and money market deposits	11,808	3,533	7,128
Time deposits	22,124	23,766	45,765
Advances from the Federal Home Loan Bank	15,092	8,595	13,168
Senior notes	3,766	3,768	1,968
Subordinated notes	1,172	0	0
Junior subordinated debentures	3,030	2,449	2,533
Securities sold under agreements to repurchase	1	1	1
Total interest expense	72,111	42,703	71,002
Net interest income	266,665	205,141	189,552
Provision for (reversal of) credit losses	13,945	(16,500)	88,620
Net interest income after provision for (reversal of) credit losses	252,720	221,641	100,932
Noninterest income
Deposits and service fees	18,592	17,214	15,838
Brokerage, advisory and fiduciary activities	17,708	18,616	16,949
Gain (loss) on early extinguishment of advances from the Federal Home Loan Bank, net	10,678	(2,488)	(73)
Loan level derivative income	10,360	3,951	3,173
Change in cash surrender value of bank owned life insurance	5,406	5,459	5,695
Cards and trade finance servicing fees	2,276	1,771	1,346
Derivative gains, net	455	0	0
Gain on sale of headquarters building	0	62,387	0
Securities (losses) gains, net	(3,689)	3,740	26,990
Other noninterest income	5,491	9,971	3,552
Total noninterest income	67,277	120,621	73,470
Noninterest expense
Salaries and employee benefits	123,510	117,585	111,469
Occupancy and equipment	27,393	20,364	17,624
Professional and other services fees	22,142	19,096	13,129
Telecommunication and data processing	14,735	14,949	12,931
Advertising expenses	11,620	3,382	1,600
Loan level derivative expense	8,146	815	330
Contract termination costs	7,103	0	0
FDIC assessments and insurance	6,598	6,423	6,141
Depreciation and amortization	5,883	7,269	9,385
Other real estate owned valuation expense	3,408	0	0
Loans held for sale valuation expense	159	0	0
Other operating expenses	10,716	8,359	6,127
Total noninterest expenses	241,413	198,242	178,736
Income (loss) before income tax (expense) benefit	78,584	144,020	(4,334)
Income tax (expense) benefit	(16,621)	(33,709)	2,612
Net income (loss) before attribution of noncontrolling interest	61,963	110,311	(1,722)
Noncontrolling interest	(1,347)	(2,610)	0
Net income (loss) attributable to Amerant Bancorp Inc.	63,310	112,921	(1,722)
Other comprehensive (loss) income, net of tax
Net unrealized holding (losses) gains on debt securities available for sale arising during the period	(97,151)	(12,960)	39,941
Net unrealized holding gains (losses) on cash flow hedges arising during the period	220	137	(1,730)
Reclassification adjustment for items included in net income	1,079	(3,624)	(19,781)
Other comprehensive (loss) income	(95,852)	(16,447)	18,430
Comprehensive (loss) income	$ (32,542)	$ 96,474	$ 16,708
Earnings (Loss) Per Share (Note 23)
Basic earnings (loss) per common share (in dollars per share)	$ 1.87	$ 3.04	$ (0.04)
Diluted earnings (loss) per common share (in dollars per share)	$ 1.85	$ 3.01	$ (0.04)