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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 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 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

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- Definition

Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ References

+ Details

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- Definition

Earliest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ References

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- Definition

The interest rate applicable to 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.

+ 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

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- Definition

+ References

+ Details

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- Details

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Financing Activities - Other Borrowings (Parenthetical) (Detail)	3 Months Ended
	Mar. 31, 2015	Aug. 31, 2014
Old National Bancorp [Member]
Debt Instrument [Line Items]
Maturity, Start date	Mar. 01, 2035
Maturity, End date	Jun. 01, 2037
Old National Bank [Member]
Debt Instrument [Line Items]
Maturity, Start date	May 01, 2015
Maturity, End date	Jan. 01, 2025
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Fixed rates		4.125%
Maturity date	Aug. 15, 2024
Senior Unsecured Notes [Member] \| Old National Bancorp [Member]
Debt Instrument [Line Items]
Fixed rates	4.125%
Maturity date	Aug. 15, 2024
Securities Sold under Agreements to Repurchase [Member] \| Old National Bank [Member]
Debt Instrument [Line Items]
Maturity, Start date	Jan. 01, 2017
Maturity, End date	Jan. 01, 2018
Minimum [Member] \| Junior Subordinated Debt [Member] \| Old National Bancorp [Member]
Debt Instrument [Line Items]
Variable rates	1.61%
Minimum [Member] \| Securities Sold under Agreements to Repurchase [Member] \| Old National Bank [Member]
Debt Instrument [Line Items]
Fixed rates	2.47%
Minimum [Member] \| Federal Home Loan Bank Advances [Member] \| Old National Bank [Member]
Debt Instrument [Line Items]
Fixed rates	0.29%
Variable rates	0.39%
Maximum [Member] \| Junior Subordinated Debt [Member] \| Old National Bancorp [Member]
Debt Instrument [Line Items]
Variable rates	2.02%
Maximum [Member] \| Securities Sold under Agreements to Repurchase [Member] \| Old National Bank [Member]
Debt Instrument [Line Items]
Fixed rates	2.50%
Maximum [Member] \| Federal Home Loan Bank Advances [Member] \| Old National Bank [Member]
Debt Instrument [Line Items]
Fixed rates	6.76%
Variable rates	0.41%