XML 50 R41.htm IDEA: XBRL DOCUMENT
v3.23.3

Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Available-for-sale Securities [Abstract] |  |
Amortized cost | $ 507,632 | $ 436,183
Gross Unrealized Gains | 729 | 493
Gross Unrealized Losses | (57,534) | (46,292)
Fair Value | 450,827 | 390,384
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] |  |
Held-to-maturity securities, amortized cost | 232,249 | 189,168
Held-to-maturity securities, Gross Unrealized Gains | 0 | 0
Held-to-maturity securities, Gross Unrealized Losses | (30,599) | (20,685)
Held-to-maturity, at fair value | 201,650 | 168,483
Held-to-maturity, debt securities, allowance for credit loss | (321) |
Held-to-maturity, debt securities, after allowance for credit loss | 231,928 | 189,168
Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value | 450,827 | 390,384
U.S. Government-sponsored agencies |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 98,594 | 35,606
Gross Unrealized Gains | 550 | 0
Gross Unrealized Losses | (1,966) | (1,797)
Fair Value | 97,178 | 33,809
U.S. Government-sponsored agencies | Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value | 97,178 | 33,809
Municipal securities |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 69,031 | 68,958
Gross Unrealized Gains | 64 | 458
Gross Unrealized Losses | (6,323) | (2,140)
Fair Value | 62,772 | 67,276
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] |  |
Held-to-maturity securities, amortized cost | 13,903 | 13,946
Held-to-maturity securities, Gross Unrealized Gains | 0 | 0
Held-to-maturity securities, Gross Unrealized Losses | (1,454) | (1,114)
Held-to-maturity, at fair value | 12,449 | 12,832
Held-to-maturity, debt securities, allowance for credit loss | (3) |
Held-to-maturity, debt securities, after allowance for credit loss | 13,900 |
Municipal securities | Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value | 62,772 | 67,276
Agency mortgage-backed securities - residential 1 |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 235,468 | 252,066
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | (42,372) | (36,974)
Fair Value | 193,096 | 215,092
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] |  |
Held-to-maturity securities, amortized cost | 170,524 | 121,853
Held-to-maturity securities, Gross Unrealized Gains |  | 0
Held-to-maturity securities, Gross Unrealized Losses |  | (15,112)
Held-to-maturity, at fair value | 147,412 | 106,741
Discount (premium) on debt securities | 400 |
Agency mortgage-backed securities - residential 1 | Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value |  | 215,092
Agency mortgage-backed securities - commercial |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 37,931 | 17,142
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | (1,768) | (1,302)
Fair Value | 36,163 | 15,840
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] |  |
Held-to-maturity securities, amortized cost | 5,782 | 5,818
Held-to-maturity securities, Gross Unrealized Gains | 0 | 0
Held-to-maturity securities, Gross Unrealized Losses | (1,592) | (1,266)
Held-to-maturity, at fair value | 4,190 | 4,552
Held-to-maturity, debt securities, allowance for credit loss | 0 |
Held-to-maturity, debt securities, after allowance for credit loss | 5,782 |
Agency mortgage-backed securities - commercial | Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value | 36,163 | 15,840
Private label mortgage-backed securities - residential |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 20,292 | 11,777
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | (1,716) | (1,322)
Fair Value | 18,576 | 10,455
Asset-backed securities |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 6,713 | 5,000
Gross Unrealized Gains | 2 | 0
Gross Unrealized Losses | (12) | (40)
Fair Value | 6,703 | 4,960
Asset-backed securities | Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value | 6,703 | 4,960
Corporate securities |  |
Available-for-sale Securities [Abstract] |  |
Amortized cost | 39,603 | 45,634
Gross Unrealized Gains | 113 | 35
Gross Unrealized Losses | (3,377) | (2,717)
Fair Value | 36,339 | 42,952
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] |  |
Held-to-maturity securities, amortized cost | 42,040 | 47,551
Held-to-maturity securities, Gross Unrealized Gains | 0 | 0
Held-to-maturity securities, Gross Unrealized Losses | (4,441) | (3,193)
Held-to-maturity, at fair value | 37,599 | 44,358
Held-to-maturity, debt securities, allowance for credit loss | (318) |
Held-to-maturity, debt securities, after allowance for credit loss | 41,722 |
Corporate securities | Significant Other Observable Inputs (Level 2) |  |
Available-for-sale Securities [Abstract] |  |
Fair Value | 36,339 | $ 42,952
Mortgage-backed securities - residential |  |
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract] |  |
Held-to-maturity securities, amortized cost | 170,524 |
Held-to-maturity securities, Gross Unrealized Gains | 0 |
Held-to-maturity securities, Gross Unrealized Losses | (23,112) |
Held-to-maturity, at fair value | 147,412 |
Held-to-maturity, debt securities, allowance for credit loss | 0 |
Held-to-maturity, debt securities, after allowance for credit loss | $ 170,524 |

X
- Definition Debt Securities, Held-to-Maturity, Discount (Premium) + References No definition available. + Details
Name: | inbk_DebtSecuritiesHeldToMaturityDiscountPremium
Namespace Prefix: | inbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481830/320-10-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (aaa) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481830/320-10-45-1 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-14 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 7A -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-7A + Details
Name: | us-gaap_HeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5A Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 + Details
Name: | us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5A -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5A Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 + Details
Name: | us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5A Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 4: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-5 + Details
Name: | us-gaap_HeldToMaturitySecuritiesFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |