Consolidated Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Securities available-for-sale, amortized cost	$ 1,163,893	$ 1,262,761
Securities held-to-maturity, fair value	$ 347,110	$ 256,672
Preferred Stock, Shares Authorized	200,000	200,000
Preferred Stock, Shares Issued	0	0
Common stock no par value	$ 0	$ 0
Common stock shares authorized	20,000,000	20,000,000
Common stock shares issued	16,150,769	16,150,807
Treasury stock shares	873,708	810,089