Name:	inbk_CarryingValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents an amount a bank borrows from the Federal Home Loan Bank stock as of the balance sheet date.

No definition available.

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A time deposit is an interest-bearing deposit held by a bank or financial institution for a fixed term whereby the depositor can only withdraw the funds after giving notice.

No definition available.

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The fair value of time deposit is an interest-bearing deposit held by a bank or financial institution for a fixed term whereby the depositor can only withdraw the funds after giving notice.

No definition available.

Name:	inbk_InterestBearingTimeDepositsFairValue
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Period Type:	instant

No definition available.

Name:	inbk_InterestPayableAtFairValue
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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. This item represents interest receivable as presented on the statement of financial position which are due the Company as of the balance sheet date.

No definition available.

Name:	inbk_InterestReceivableAtFairValue
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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 45

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Name:	us-gaap_AdvancesFromFederalHomeLoanBanks
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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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-Name Accounting Standards Codification

-Glossary Cash

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-Glossary Cash Equivalents

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

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-Topic 210

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-Paragraph 1

-Subparagraph (a)

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-Topic 230

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3044-108585

Name:	us-gaap_CashAndCashEquivalentsAtCarryingValue
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

Name:	us-gaap_Deposits
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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

No definition available.

Name:	us-gaap_DepositsFairValueDisclosure
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Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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-Topic 820

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-Section 50

-Paragraph 2

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Name:	us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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-Topic 942

-SubTopic 325

-Section 45

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Name:	us-gaap_FederalHomeLoanBankStock
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Amount of interest payable on debt, including, but not limited to, trade payables.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

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-Topic 944

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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-Topic 210

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-Article 5

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

No definition available.

Name:	us-gaap_LoansHeldForSaleFairValueDisclosure
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Amount of mortgage loans held for sale. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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-Subparagraph (SX 210.9-03.7(a)(3))

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-Topic 948

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-Section 45

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-Glossary Permanent Investor

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Name:	us-gaap_LoansHeldForSaleMortgages
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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Topic 310

-SubTopic 10

-Glossary Loan

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Name:	us-gaap_LoansReceivableFairValueDisclosure
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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph a

-Article 9

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

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-Subparagraph (SX 210.9-03.7(a))

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