Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets
Available-for-sale investment securities at amortized cost	$ 785,544	$ 780,304
Held-to-maturity investment securities at fair value	$ 46,202	$ 45,853
Stockholders’ equity
Preferred stock - shares authorized	50,000	50,000
Preferred stock - shares issued	0	0
Common stock - shares authorized	24,000,000	24,000,000
Common stock - shares issued	18,934,185	18,931,200
Treasury stock - shares	831,018	586,688