Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of common shares issued	0	0	493,920
Stock Repurchased and Retired During Period, Shares	0	0	100,000
Common Stock, Dividends, Per Share, Declared	$ 0.44	$ 0.40	$ 0.32
Common stock issuances from reinvested dividends, number of shares	6,950	5,203	5,745
Stock Issued During Period, Shares, Acquisitions	1,537,912
Purchase of unallocated common stock held by ESOP, number of shares	0	0	208,333
Stock Issued During Period, Shares, Employee Stock Ownership Plan	39,805	35,283	26,511
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	18,340	24,740	6,560