Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investment securities held to maturity, at fair value	$ 483,994	$ 463,799
Loans receivable, allowance for loan losses	$ 7,566	$ 8,599
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	59,288,698	57,518,609
Common stock, shares outstanding (in shares)	58,759,853	56,989,764
Treasury stock (in shares)	503,408	503,408
Stock held by deferred compensation plan (in shares)	25,437	25,437