XML 118 R103.htm IDEA: XBRL DOCUMENT v3.21.1

Commitments and Contingencies (Detail)	3 Months Ended
	Mar. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)
Loss Contingencies [Line Items]
Loan commitments	$ 3,851,000,000	$ 3,720,000,000
Standby letters of credit	75,100,000	86,900,000
Fixed rate loan commitment	3,613,000,000
Floating rate loan commitment	$ 238,300,000
Loan commitments floating rate, minimum	0.00%
Loan commitments floating rate, maximum	14.00%
Allowance for unfunded loan commitments	$ 10,400,000	11,700,000
Extended credit	7,900,000	7,900,000
Credit extensions with collateral	$ 7,500,000	$ 7,500,000
Class B Restricted Shares | Visa
Loss Contingencies [Line Items]
Restricted stock conversion ratio	1.6228
Investment owned, balance, shares | shares	65,466
Investment owned, at cost	$ 0

X

- Definition

Amount of valuation allowance recorded for unfunded commitments to extend credit.

+ References

No definition available.

+ Details

Name:	onb_AllowanceForUnfundedLoanCommitments
Namespace Prefix:	onb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of credit extended with unaffiliated banks related to letter of credit commitments issued on behalf of our clients.

+ References

No definition available.

+ Details

Name:	onb_CreditExtended
Namespace Prefix:	onb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of collateral provided to secure credit extended with unaffiliated banks related to letter of credit commitments issued on behalf of our clients.

+ References

No definition available.

+ Details

Name:	onb_CreditExtensionsWithCollateral
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 loan.

+ References

No definition available.

+ Details

Name:	onb_LoanCommitments
Namespace Prefix:	onb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Maximum floating rate percentage charged on loan commitments.

+ References

No definition available.

+ Details

Name:	onb_LoanCommitmentsFloatingInterestRateMaximum
Namespace Prefix:	onb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Minimum floating rate percentage charged on loan commitments.

+ References

No definition available.

+ Details

Name:	onb_LoanCommitmentsFloatingInterestRateMinimum
Namespace Prefix:	onb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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

Restricted stock conversion ratio.

+ References

No definition available.

+ Details

Name:	onb_RestrictedStockConversionRatio
Namespace Prefix:	onb_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Cost of the investment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841

+ Details

Name:	us-gaap_InvestmentOwnedAtCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Balance held at close of period in number of shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section 50
-Paragraph 6
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-12B(Column B))
-URI http://asc.fasb.org/extlink&oid=120401592&loc=d3e611197-123010

+ Details

Name:	us-gaap_InvestmentOwnedBalanceShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61082-112788

+ Details

Name:	us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61082-112788

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788

+ Details

Name:	us-gaap_LoansAndLeasesReceivableCommitmentsVariableRates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_InvestmentTypeAxis=onb_ClassBRestrictedSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentSecondaryCategorizationAxis=onb_VisaIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: