ASC Eight One Five Fair Value Hedge and Other Basis Adjustments

Name:	onb_AscEightOneFiveFairValueHedgeAndOtherBasisAdjustments
Namespace Prefix:	onb
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 7

+ Details

Name:	us-gaap_CapitalLeaseObligations
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

When presenting a range of maturity dates, the latest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years).

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDateRangeEnd
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

When presenting a range of maturity dates, the earliest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years).

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDateRangeStart
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 47
-Paragraph 10

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 15, 18
-Subsection I

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-DEP
-Chapter 15
-Paragraph 37
-IssueDate 2006-05-01

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 14
-Subparagraph f

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

+ Details

Name:	us-gaap_FederalHomeLoanBankAdvancesLongTerm
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

+ Details

Name:	us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 13, 16
-Article 9

+ Details

Name:	us-gaap_JuniorSubordinatedNotes
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance-sheet date, including current maturities, which accrues interest at a set, unchanging rate

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingFixedInterestRate
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance-sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 13, 16
-Article 9

+ Details

Name:	us-gaap_OtherBorrowings
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of securities that an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price, also known as a repurchase agreement, or repo. Most repos involve obligations of the federal government or its agencies, but other financial instruments, such as commercial paper, banker's acceptances, and negotiable certificates of deposit, are sometimes used in repos.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 13
-Subparagraph 1
-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 140
-Paragraph 100

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-BRD
-Chapter 4
-Paragraph 36
-IssueDate 2006-05-01

+ Details

Name:	us-gaap_SecuritiesSoldUnderAgreementsToRepurchase
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Financing Activities (Other Borrowings) (Details) (USD $) In Thousands, unless otherwise specified			6 Months Ended			6 Months Ended		6 Months Ended			6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Securities Sold Under Agreements To Repurchase [Member]	Jun. 30, 2011 Maximum [Member] Junior Subordinated Debenture [Member]	Jun. 30, 2011 Minimum [Member] Junior Subordinated Debenture [Member]	Jun. 30, 2011 Junior Subordinated Debenture [Member]	Jun. 30, 2011 Old National Bancorp [Member] Subordinated Notes [Member]	Jun. 30, 2011 Subordinated Notes [Member]	Jun. 30, 2011 Maximum [Member] Federal Home Loan Bank Advances [Member]	Jun. 30, 2011 Minimum [Member] Federal Home Loan Bank Advances [Member]	Jun. 30, 2011 Federal Home Loan Bank Advances [Member]	Jun. 30, 2011 Subordinated Bank Notes [Member] Old National Bank [Member]	Jun. 30, 2011 Old National Bancorp [Member]	Dec. 31, 2010 Old National Bancorp [Member]	Jun. 30, 2011 Old National Bank [Member]	Dec. 31, 2010 Old National Bank [Member]
Junior subordinated debenture (variable rates of 2.00% to 3.30% and fixed rates of 6.52% to 7.15%) maturing July 2033 to June 2037													$ 16,000	$ 8,000
Junior subordinated debenture													13,000	0	150,000	150,000
ASC 815 fair value hedge and other basis adjustments													(2,648)	(36)	(1,482)	(2,056)
Securities sold under agreements to repurchase (variable rate 3.07%) maturing October 2014															50,000	50,000
Federal Home Loan Bank advances (fixed rates 1.24% to 8.34% and variable rate 3.47%) maturing June 2012 to January 2023															211,316	211,696
Capital lease obligation															4,284	4,307
Total other borrowings	$ 440,470	$ 421,911
Variable rates			3.07%	3.30%	2.00%						3.47%
Fixed rates				7.15%	6.52%		10.00%		8.34%	1.24%		6.75%
Maturity, Start date						July 2033					June 2012
Maturity, End date						June 2037					January 2023
Maturity date			Oct. 01, 2014					Jun. 01, 2019