Business Combinations Narrative (FCL) (Details)	Sep. 08, 2016 USD ($) $ / shares shares	Mar. 31, 2017 $ / shares	Dec. 31, 2016 $ / shares
Business Acquisition [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 4	$ 4
Goodwill, Acquired During Period	$ 16,785,000
First Clover Leaf [Member]
Business Acquisition [Line Items]
Percent Of Acquiree Outstanding Stock Being Acquired In Merger	1.00
Percentage of business acquisition consideration paid in cash	25.00%
Right To Receive Value of Cash Option | $ / shares	$ 12.87
Aggregate Total Of Cash Paid In Business Combination	$ 22,545,000
Portion of Business Acquisition Consideration Paid In Common Stock	75.00%
Right To Receive Value Of Share Option | shares	0.495
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	2,600,616
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 668,905,000
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Loans	438,265,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	536,686,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Premises And Equipment	11,581,000
Goodwill, Acquired During Period	16,800,000
Business Acquisition Deposit Premium on Core Deposits	8,741,000
Acquired Book Value [Member] | First Clover Leaf [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	658,788,000
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Loans	448,668,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	534,692,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Premises And Equipment	$ 9,618,000