v3.21.2

DEPOSITS - Additional Information (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
DEPOSITS |  |
Certificates of deposits of $250,000 or more, maturities within one year | $ 342 | $ 409
Certificates of deposits of $250,000 or more, maturities after one year | 2 | 7
Certificates of deposits of $250,000 or more, total | 344 | 416
Certificates of deposit of less than $ 250,000, maturities within one year | 260 | 520
Certificates of deposit of less than $ 250,000, maturities after one year | 9 | 43
Certificates of deposit of less than $250,000, total | $ 269 | $ 563

X
- Definition Time deposits 250000 or more. + References No definition available. + Details
Name: | ffwm_TimeDeposits250000OrMore
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Time deposits 250000 or more, maturities after one year. + References No definition available. + Details
Name: | ffwm_TimeDeposits250000OrMoreMaturitiesAfterOneYear
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Time deposits 250000 or more, maturities with in one year. + References No definition available. + Details
Name: | ffwm_TimeDeposits250000OrMoreMaturitiesWithInOneYear
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Time deposits less than 250000. + References No definition available. + Details
Name: | ffwm_TimeDepositsLessThan250000
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Time deposits less than 250000, maturities after one year. + References No definition available. + Details
Name: | ffwm_TimeDepositsLessThan250000MaturitiesAfterOneYear
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Time deposits less than 250000, maturities with in one year. + References No definition available. + Details
Name: | ffwm_TimeDepositsLessThan250000MaturitiesWithInOneYear
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DepositsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration