Business, Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)							1 Months Ended		3 Months Ended
	Apr. 19, 2023 $ / shares	Feb. 28, 2023 USD ($)	Jan. 18, 2023 $ / shares	Jan. 13, 2023 USD ($)	Feb. 28, 2022 USD ($)	Jan. 19, 2022 $ / shares	Apr. 30, 2023 USD ($)	Jan. 31, 2022 USD ($) shares	Mar. 31, 2023 USD ($) subsidiary $ / shares shares	Mar. 31, 2022 USD ($) shares	Dec. 31, 2022 USD ($) $ / shares	Dec. 19, 2022 USD ($)
Class of Stock [Line Items]
Number of subsidiaries | subsidiary									3
Common stock, par value (in dollars per share) | $ / shares									$ 0.10		$ 0.10
Severance expense									$ 200,000	$ 800,000
Professional and other services fees									7,628,000	6,139,000
Restructuring costs									500,000
Other restructuring expense										1,300,000
Gain (loss) on early extinguishment of advances from the Federal Home Loan Bank, net									13,173,000	(714,000)
Goodwill									$ 20,525,000		$ 19,506,000
Subsequent Event
Class of Stock [Line Items]
Gain (loss) on early extinguishment of advances from the Federal Home Loan Bank, net							$ 4,000,000
Amount repaid							$ 175,000,000
F&B Acquisition Group LLC
Class of Stock [Line Items]
Payments to acquire businesses				$ 2,000,000
Loans held for sale at fair value				1,000,000
Goodwill				$ 1,000,000
New Class A Common Stock Repurchase Program
Class of Stock [Line Items]
Treasury stock acquired (in dollars per share) | $ / shares									$ 32.96
Contract Termination
Class of Stock [Line Items]
Professional and other services fees									$ 2,700,000
Restructuring costs										$ 4,000,000
Class A Common Stock
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares									$ 0.10
Treasury stock (in shares) | shares									0	0
Dividends declared (in dollars per share) | $ / shares			$ 0.09			$ 0.09
Dividend paid		$ 3,000,000			$ 3,200,000
Class A Common Stock | Subsequent Event
Class of Stock [Line Items]
Dividends declared (in dollars per share) | $ / shares	$ 0.09
Class A Common Stock | 2023 Class A Common Stock Repurchase Program Member
Class of Stock [Line Items]
Stock repurchase program, authorized amount												$ 25,000,000
Treasury stock, acquired (in shares) | shares									22,403
Treasury stock acquired									$ 600,000
Class A Common Stock | 2021 Class A Common Stock Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount								$ 50,000,000
Treasury stock, acquired (in shares) | shares								652,118
Treasury stock acquired								$ 22,100,000
Class A Common Stock | New Class A Common Stock Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount								$ 50,000,000
Treasury stock, acquired (in shares) | shares									991,362
Treasury stock acquired									$ 32,700,000
Amerant Bank, N.A
Class of Stock [Line Items]
Ownership percentage of subsidiary									100.00%