Business Combinations Pro Forma Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
SCB Bancorp [Member]
Business Acquisition [Line Items]
Business Acquisitions Pro Forma Net Interest Income	$ 123,161	$ 105,925
Business Acquisitions Pro Forma Provision For Loan Losses	8,667	7,462
Business Acquisitions Pro Forma Non-Interest Income	52,257	47,719
Business Acquisitions Pro Forma Non-Interest Expense	112,246	100,933
Business Acquisitions Pro Forma Income before Income Taxes	54,505	45,249
Business Acquisitions Pro Forma, Income Tax Expense	12,711	16,352
Business Acquisition, Pro Forma Net Income (Loss)	$ 41,794	$ 28,897
Pro Forma Earnings Per Share
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 2,670	$ 2,080
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 2,670	$ 2,080
Weighted Average Basic Shares Outstanding, Pro Forma	15,646,359	13,862,230
Pro Forma Weighted Average Shares Outstanding, Diluted	15,659,818	13,867,105
First BancTrust [Member]
Business Acquisition [Line Items]
Business Acquisitions Pro Forma Net Interest Income	$ 117,450	$ 110,990
Business Acquisitions Pro Forma Provision For Loan Losses	8,867	8,365
Business Acquisitions Pro Forma Non-Interest Income	36,526	34,060
Business Acquisitions Pro Forma Non-Interest Expense	94,464	94,843
Business Acquisitions Pro Forma Income before Income Taxes	50,645	41,842
Business Acquisitions Pro Forma, Income Tax Expense	12,456	15,849
Business Acquisition, Pro Forma Net Income (Loss)	$ 38,189	$ 25,993
Pro Forma Earnings Per Share
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 2,600	$ 1,830
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 2,590	$ 1,830
Weighted Average Basic Shares Outstanding, Pro Forma	14,704,888	14,175,559
Pro Forma Weighted Average Shares Outstanding, Diluted	14,721,708	14,180,434