Business Combinations Narrative (ONB) (Details)		9 Months Ended
	Sep. 08, 2016 USD ($)	Sep. 30, 2016 branch	Dec. 31, 2015 USD ($)	Aug. 14, 2015 USD ($)
OldNationalBankBranches [Member]
Business Acquisition [Line Items]
number of bank branches acquired | branch		12
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits			$ 453,000,000	$ 453,647,000
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Loans			$ 156,000,000	$ 152,397,000
Business Acquisition Deposit Premium Rate On Core Deposits				0.036
Business Acquisition Deposit Premium on Core Deposits				$ 15,892,000
Business Combinations Fixed Deposit Premium For Municipal Deposits				500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Premises And Equipment				4,422,000
OldNationalBankBranches [Member] | Acquired Book Value [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits				452,810,000
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Loans				155,774,000
Business Combination Recognized Identifiable Assets Acquired and LIabilities Assumed, cash on hand				2,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Premises And Equipment				4,547,000
Business Combination Cash Settlement				$ 276,800,000
First Clover Leaf [Member]
Business Acquisition [Line Items]
Percent Of Acquiree Outstanding Stock Being Acquired In Merger	1.00
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	$ 536,686,000
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Loans	438,265,000
Business Acquisition Deposit Premium on Core Deposits	8,741,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Premises And Equipment	11,581,000
First Clover Leaf [Member] | Acquired Book Value [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	534,692,000
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Loans	448,668,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Premises And Equipment	$ 9,618,000