XML 149 R134.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Financial Guarantees (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Derivative [Line Items] |  |
Term of standby letters of credit, years | 1 year |
Notional amount of standby letters of credit | $ 75.7 | $ 86.9
Carrying value of letters of credit | 0.5 | $ 0.5
Interest Rate Swap |  |
Derivative [Line Items] |  |
Notional amount | $ 97.7 |

X
- Definition Carrying value of standby letters of credit financial instruments. + References No definition available. + Details
Name: | onb_CarryingValueOfLetterOfCredit
Namespace Prefix: | onb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of agreement to extend credit in the form of a standby letter of credit. + References No definition available. + Details
Name: | onb_NotionalAmountOfStandbyLettersOfCredit
Namespace Prefix: | onb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Length of time that standby letters of credit are effective. + References No definition available. + Details
Name: | onb_TermOfStandbyLettersOfCredit
Namespace Prefix: | onb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |