XML 75 R60.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Basis of Presentation and Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Property, Plant and Equipment [Line Items] |  |
Loans held for sale, at fair value | $ 35,458 | $ 63,250
Residential Mortgage Loans |  |
Property, Plant and Equipment [Line Items] |  |
Loans held for sale, at fair value | $ 35,500 | $ 63,300
Minimum |  |
Property, Plant and Equipment [Line Items] |  |
Maturity of short-term securities sold under agreements to repurchase | 1 day |
Minimum | Core Deposits and Other Intangible Assets |  |
Property, Plant and Equipment [Line Items] |  |
Estimated useful lives of core deposits and customer relationships | 5 years |
Minimum | Building and Building Improvements |  |
Property, Plant and Equipment [Line Items] |  |
Useful lives for premises and equipment, years | 10 years |
Minimum | Furniture and Equipment |  |
Property, Plant and Equipment [Line Items] |  |
Useful lives for premises and equipment, years | 3 years |
Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Maturity of short-term securities sold under agreements to repurchase | 4 days |
Maximum | Core Deposits and Other Intangible Assets |  |
Property, Plant and Equipment [Line Items] |  |
Estimated useful lives of core deposits and customer relationships | 15 years |
Maximum | Building and Building Improvements |  |
Property, Plant and Equipment [Line Items] |  |
Useful lives for premises and equipment, years | 39 years |
Maximum | Furniture and Equipment |  |
Property, Plant and Equipment [Line Items] |  |
Useful lives for premises and equipment, years | 7 years |

X
- Definition Number of days from transaction date that securities sold under agreement to repurchase mature. + References No definition available. + Details
Name: | onb_MaturityOfSecuritiesSoldUnderAgreementToRepurchase
Namespace Prefix: | onb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 310 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124265262&loc=d3e48678-111004 + Details
Name: | us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=onb_CoreDepositsAndOtherIntangibleAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingAndBuildingImprovementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_FurnitureAndFixturesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |