Defined contribution plans employee contribution percentage of eligible compensation matched by employer.

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- Definition

The number of company shares in the 401(k) plan. Company shares owned through the 401(k) plan are included in the calculation of weighted-average shares outstanding for purposes of calculating basic and diluted earnings-per-share.

+ References

No definition available.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

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- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

+ References

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

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- 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.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

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- Definition

An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

+ References

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

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Share-Based Compensation and Other Employee Benefit Plans - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares available for issuance (in shares)		2,900,000
Stock based compensation expense		$ 7,700,000	$ 8,000,000.0	$ 8,100,000
Total income tax benefit, stock-based compensation cost		1,900,000	2,000,000.0	2,000,000.0
Discretionary profit sharing		$ 0	$ 0	0
Shares allocated to the employee stock ownership plan (in shares)		600,000	600,000
Contribution expense under employee stock ownership plan		$ 9,500,000	$ 9,800,000	8,600,000
Employer Matching Contribution Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contribution plan, employer matching contribution percentage	75.00%
Defined contribution plans employee contribution percentage of eligible compensation matched by employer	4.00%
Employer Matching Contribution Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contribution plan, employer matching contribution percentage	50.00%
Defined contribution plans employee contribution percentage of eligible compensation matched by employer	4.00%
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation awards, vesting period		3 years
Unrecognized compensation expense		$ 5,700,000
Expected weighted-average period for cost recognition (in years)		2 years 1 month 6 days
Total fair value of shares vested		$ 2,900,000	$ 3,400,000	$ 3,400,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation awards, vesting period		3 years
Unrecognized compensation expense		$ 3,600,000
Expected weighted-average period for cost recognition (in years)		1 year 8 months 12 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term, in years		10 years
Stock Options \| Old National Bancorp
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental expense associated with conversion of stock awards		$ 0
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation awards, vesting period		3 years
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation awards, vesting period		5 years
Outside Director Stock Compensation Program \| Amended and Restated 2008 Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)		28,000	12,000	16,000