v3.8.0.1

Loans - Composition of TDRs by Accrual and Nonaccrual Status (Details) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Accounts Notes And Loans Receivable [Line Items] |  |
Troubled Debt Restructurings, Nonaccrual | $ 11,359 | $ 8,238
Troubled Debt Restructurings, Total | 4,500 | 3,400
Commercial and Industrial Loans |  |
Accounts Notes And Loans Receivable [Line Items] |  |
Troubled Debt Restructurings, Nonaccrual | 9,617 | 3,359
Principal Reduction and Extended Maturity | Commercial and Industrial Loans |  |
Accounts Notes And Loans Receivable [Line Items] |  |
Troubled Debt Restructurings, Accrual | 195 | 317
Troubled Debt Restructurings, Nonaccrual | 4,296 | 3,109
Troubled Debt Restructurings, Total | $ 4,491 | $ 3,426

X
- Definition Financing receivable recorded investment accrual status. + References No definition available. + Details
Name: | ffwm_FinancingReceivableRecordedInvestmentAccrualStatus
Namespace Prefix: | ffwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=ffwm_PrincipalReductionAndExtendedMaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |