XML 60 R50.htm IDEA: XBRL DOCUMENT
v3.21.2

Loans - Impaired Loans (Details) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 USD ($) loan | Sep. 30, 2020 USD ($) security | Sep. 30, 2021 USD ($) loan | Sep. 30, 2020 USD ($) | Dec. 31, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | $ 6,943,000 |  | $ 6,943,000 |  | $ 6,276,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 7,292,000 |  | 7,292,000 |  | 6,483,000
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Impaired loans | 3,748,000 |  | 3,748,000 |  | 6,009,000
Loans with a specific valuation allowance - Unpaid Principal Balance | 3,794,000 |  | 3,794,000 |  | 6,036,000
Loans with a specific valuation allowance | 1,461,000 |  | 1,461,000 |  | 3,090,000
Impaired Financing Receivable, Recorded Investment | 10,691,000 |  | 10,691,000 |  | 12,285,000
Impaired Financing Receivable, Unpaid Principal Balance | 11,086,000 |  | 11,086,000 |  | 12,519,000
Impaired Financing Receivable, Related Allowance | 1,461,000 |  | 1,461,000 |  | 3,090,000
Loans without a specific valuation allowance - Average Balance | 7,076,000 | $ 6,550,000 | 7,175,000 | $ 7,034,000 |
Loans without a specific valuation allowance - Interest Income | 15,000 | 55,000 | 42,000 | 122,000 |
Loans with a specific valuation allowance - Average Balance | 4,897,000 | 6,160,000 | 7,235,000 | 5,309,000 |
Loans with a specific valuation allowance - Interest Income | 37,000 | 51,000 | 73,000 | 51,000 |
Impaired Financing Receivable, Average Recorded Investment | 11,973,000 | 12,710,000 | 14,410,000 | 12,343,000 |
Impaired Financing Receivable, Interest Income, Accrual Method | 52,000 | $ 106,000 | 115,000 | 173,000 |
Other real estate owned | $ 1,188,000 |  | $ 1,188,000 |  | 0
Mortgage loans in process of foreclosure, number of loans | loan | 2 |  | 2 |  |
Mortgage loans in process of foreclosure, amount | $ 400,000 |  | $ 400,000 |  | 0
Number of contracts classified as TDRs | security |  | 0 |  |  |
Commercial and industrial |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 3,429,000 |  | 3,429,000 |  | 517,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 3,486,000 |  | 3,486,000 |  | 517,000
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Impaired loans | 678,000 |  | 678,000 |  | 0
Loans with a specific valuation allowance - Unpaid Principal Balance | 701,000 |  | 701,000 |  | 0
Loans with a specific valuation allowance | 450,000 |  | 450,000 |  | 0
Loans without a specific valuation allowance - Average Balance | 0 | $ 971,000 | 259,000 | 1,210,000 |
Loans without a specific valuation allowance - Interest Income | 0 | 18,000 | 9,000 | 54,000 |
Loans with a specific valuation allowance - Average Balance | 690,000 | 182,000 | 677,000 | 196,000 |
Loans with a specific valuation allowance - Interest Income | $ 0 | 18,000 | $ 0 | 18,000 |
Other real estate, number of loans | loan | 1 |  | 1 |  |
Owner-occupied commercial real estate |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | $ 0 |  | $ 0 |  | 1,838,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 0 |  | 0 |  | 1,850,000
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Loans without a specific valuation allowance - Average Balance | 3,457,000 | 3,586,000 | 3,297,000 | 4,244,000 |
Loans without a specific valuation allowance - Interest Income | 0 | 29,000 | 0 | 60,000 |
Loans with a specific valuation allowance - Average Balance | 0 | 0 | 473,000 | 0 |
Loans with a specific valuation allowance - Interest Income | 0 | 29,000 | 0 | 29,000 |
Single tenant lease financing |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 0 |  | 0 |  | 1,315,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 0 |  | 0 |  | 1,334,000
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Impaired loans | 1,100,000 |  | 1,100,000 |  | 6,009,000
Loans with a specific valuation allowance - Unpaid Principal Balance | 1,123,000 |  | 1,123,000 |  | 6,036,000
Loans with a specific valuation allowance | 95,000 |  | 95,000 |  | 3,090,000
Loans without a specific valuation allowance - Average Balance | 0 | 0 | 100,000 | 0 |
Loans without a specific valuation allowance - Interest Income | 0 | 0 | 5,000 | 0 |
Loans with a specific valuation allowance - Average Balance | 2,048,000 | 5,978,000 | 4,875,000 | 5,113,000 |
Loans with a specific valuation allowance - Interest Income | 0 | 4,000 | 0 | 4,000 |
Healthcare finance |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 0 |  | 0 |  | 1,010,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 0 |  | 0 |  | 1,010,000
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Impaired loans | 941,000 |  | 941,000 |  | 0
Loans with a specific valuation allowance - Unpaid Principal Balance | 941,000 |  | 941,000 |  | 0
Loans with a specific valuation allowance | 523,000 |  | 523,000 |  | 0
Loans without a specific valuation allowance - Average Balance | 0 | 692,000 | 336,000 | 231,000 |
Loans without a specific valuation allowance - Interest Income | 0 | 0 | 8,000 | 8,000 |
Loans with a specific valuation allowance - Average Balance | 956,000 | 0 | 809,000 | 0 |
Loans with a specific valuation allowance - Interest Income | 37,000 | 0 | 73,000 | 0 |
Small business lending |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 1,377,000 |  | 1,377,000 |  | 0
Loans without a specific valuation allowance - Unpaid Principal Balance | 1,486,000 |  | 1,486,000 |  | 0
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Impaired loans | 1,029,000 |  | 1,029,000 |  | 0
Loans with a specific valuation allowance - Unpaid Principal Balance | 1,029,000 |  | 1,029,000 |  | 0
Loans with a specific valuation allowance | 393,000 |  | 393,000 |  | 0
Loans without a specific valuation allowance - Average Balance | 1,315,000 | 0 | 1,005,000 | 0 |
Loans without a specific valuation allowance - Interest Income | 0 |  | 0 | 0 |
Loans with a specific valuation allowance - Average Balance | 1,203,000 | 0 | 401,000 | 0 |
Loans with a specific valuation allowance - Interest Income | 0 | 0 | 0 | 0 |
Residential mortgage |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 2,096,000 |  | 2,096,000 |  | 1,546,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 2,223,000 |  | 2,223,000 |  | 1,652,000
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Loans without a specific valuation allowance - Average Balance | 2,267,000 | 1,233,000 | 2,138,000 | 1,286,000 |
Loans without a specific valuation allowance - Interest Income | 15,000 | 0 | $ 28,000 | 0 |
Number of contracts classified as TDRs | loan |  |  | 1 |  |
Financing receivable, troubled debt restructuring | 800,000 | 800,000 | $ 800,000 | 800,000 |
Home equity |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 14,000 |  | 14,000 |  | 0
Loans without a specific valuation allowance - Unpaid Principal Balance | 15,000 |  | 15,000 |  | 0
Loans without a specific valuation allowance | 0 |  | 0 |  | 0
Loans without a specific valuation allowance - Average Balance | 14,000 | 0 | 13,000 | 0 |
Loans without a specific valuation allowance - Interest Income | 0 | 0 | 0 | 0 |
Other consumer |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans without a specific valuation allowance - Recorded Balance | 27,000 |  | 27,000 |  | 50,000
Loans without a specific valuation allowance - Unpaid Principal Balance | 82,000 |  | 82,000 |  | 120,000
Loans without a specific valuation allowance | 0 |  | 0 |  | $ 0
Loans without a specific valuation allowance - Average Balance | 23,000 | 68,000 | 27,000 | 63,000 |
Loans without a specific valuation allowance - Interest Income | $ 0 | $ 0 | $ 0 | $ 0 |

X
- Definition Amount of allowance for credit losses related to recorded investment not with a specific valuation allowance. + References No definition available. + Details
Name: | inbk_ImpairedFinancingReceivableLoansWithNoSpecificRelatedAllowance
Namespace Prefix: | inbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of allowance for credit losses related to recorded investment with specific valuation allowance. + References No definition available. + Details
Name: | inbk_ImpairedFinancingReceivableLoansWithSpecificRelatedAllowance
Namespace Prefix: | inbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Mortgage Loans In Process Of Foreclosure, Number Of Loans + References No definition available. + Details
Name: | inbk_MortgageLoansInProcessOfForeclosureNumberOfLoans
Namespace Prefix: | inbk_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Other Real Estate, Number Of Loans + References No definition available. + Details
Name: | inbk_OtherRealEstateNumberOfLoans
Namespace Prefix: | inbk_
Data Type: | xbrli:integerItemType
Balance Type: | na
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 Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of financing receivable modified as troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of allowance for credit losses related to recorded investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRelatedAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of investment in impaired financing receivables for which there is no related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of investment in impaired financing receivables for which there is a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL49126937-111524 + Details
Name: | us-gaap_MortgageLoansInProcessOfForeclosureAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10(4)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
Name: | us-gaap_OtherRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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

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

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

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

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

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