XML 57 R47.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Subordinated Debt (Details Textual) - Subordinated Debt - USD ($) |  | 9 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 28, 2013 | Jun. 28, 2013 | Sep. 30, 2018 | May 04, 2017 | Oct. 20, 2015
2021 Debenture |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Subordinated debenture, principal amount | $ 3,000,000 | $ 3,000,000 |  |  |
Fixed annual interest rate (as a percent) | 8.00% | 8.00% |  |  |
Subordinated debenture, maturity date |  | Jun. 28, 2021 |  |  |
Subordinated debenture, maturity date range, start | Jun. 28, 2016 |  |  |  |
Warrants issued to purchase common stock (in shares) | 48,750 |  |  |  |
Common stock exercise price (in dollars per share) | $ 19.33 |  |  |  |
Number of shares withheld in accordance with warrant's cashless exercise feature (in shares) |  |  |  | 32,835 |
Common stock, shares issued (in shares) |  |  |  | 15,915 |
2025 Note |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Subordinated debenture, principal amount |  |  |  |  | $ 10,000,000.0
Fixed annual interest rate (as a percent) |  |  |  |  | 6.4375%
2026 Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Subordinated debenture, principal amount |  |  | $ 25,000,000.0 |  |
Fixed annual interest rate (as a percent) |  |  | 6.00% |  |
LIBOR | 2026 Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis spread on variable rate |  |  | 485.00% |  |

X
- Definition Class Of Warrant Or Right, Number Of Securities Withheld For Cashless Exercise Feature + References No definition available. + Details
Name: | inbk_ClassOfWarrantOrRightNumberOfSecuritiesWithheldForCashlessExerciseFeature
Namespace Prefix: | inbk_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the exercise price of the common stock. + References No definition available. + Details
Name: | inbk_CommonStockExercisePrice
Namespace Prefix: | inbk_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the issue of warrants to purchase common stock during the period. + References No definition available. + Details
Name: | inbk_WarrantsIssuedToPurchaseCommonStock
Namespace Prefix: | inbk_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Earliest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateRangeStart1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SubordinatedDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=inbk_A8PercentDebentureDue2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=inbk_A6.4375PercentNotesDue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=inbk_A6PercentNotesDue2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |