XML 62 R51.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Loans and Allowance for Loan Losses - Additional Information (Details) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2017 USD ($) Loan | Sep. 30, 2016 USD ($) | Dec. 31, 2016 USD ($) Loan
Financing Receivable Recorded Investment [Line Items] |  |  |
Loans past due 90 days and still on accrual | $ 0 |  | $ 0
Interest income recognized on cash basis | $ 0 | $ 0 | $ 0
Number of loans identified as troubled debt restructurings | Loan | 5 |  | 6
Specific reserve | $ 11,420,000 |  | $ 14,162,000
Commitments to lend an additional amounts of outstanding loans are classified as TDR's | $ 0 |  | 0
Description of loans modified as troubled debt restructuring | During the year ended December 31, 2016 and for the nine months ended September 30, 2017, the terms of certain loans were modified as TDR's. The modification of the terms generally included loans where a moratorium on loan payments was granted. Such moratoriums ranged from three months to twelve months on the loans restructured in 2017 and 2016. |  |
Increase in allowance for loan losses under purchased credit-impaired loans | $ 0 |  | 0
Significant reductions in allowance for loan losses under purchased credit-impaired loans | $ 0 |  | 0
Minimum |  |  |
Financing Receivable Recorded Investment [Line Items] |  |  |
Moratorium on loan payments period granted | 3 months |  |
Maximum |  |  |
Financing Receivable Recorded Investment [Line Items] |  |  |
Moratorium on loan payments period granted | 12 months |  |
One Loan |  |  |
Financing Receivable Recorded Investment [Line Items] |  |  |
Specific reserve | $ 0 |  | $ 1,782,000

X
- Definition Certain loans acquired in transfer not accounted for as debt securities allowance for loan losses increases. + References No definition available. + Details
Name: | rbb_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLossesIncreases
Namespace Prefix: | rbb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Moratorium on loan payment period granted. + References No definition available. + Details
Name: | rbb_MoratoriumOnLoanPaymentPeriodGranted
Namespace Prefix: | rbb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings. + References No definition available. + Details
Name: | us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of reduction in the reserve for loans impairments as a result of current information and events which result in it being probable that estimated cash flows will be significantly higher than previously expected or because actual cash flows are significantly greater than cash flows previously expected for loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. + References No definition available. + Details
Name: | us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLossesDecreases1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Description of the nature and the extent of troubled debt restructurings that occurred during the period related to financing receivables. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNatureAndExtentOfTransaction1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of 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 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Recorded investment in financing receivables that are 90 days or more past due and still accruing. + 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 (d) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
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_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554 + Details
Name: | us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rbb_OneLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |