Consolidated Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Securities available-for-sale, amortized cost	$ 1,368,902	$ 1,299,980
Securities held-to-maturity, fair value	$ 123,546	$ 143,490
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	16,150,866	16,150,888
Treasury stock shares	779,989	758,489