REGULATORY MATTERS - Additional Information (Details) $ in Millions	Dec. 31, 2021 USD ($)
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital buffer against risk weighted assets cumulative	2.50%
First Foundation Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
CET1 capital ratio, to be well-capitalized amount	$ 371
Tier 1 leverage ratio, to be well-capitalized amount	353
Tier 1 risk-based capital ratio, to be well-capitalized amount	259
Excess total risk-based capital ratio, to be well-capitalized amount	$ 152