Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Investment securities held to maturity, at fair value	$ 413,699	$ 425,183
Loans receivable, allowance for loan losses	$ 9,181	$ 9,155
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)	57,415,434	57,283,712
Common stock, shares outstanding (in shares)	56,886,589	56,754,867
Treasury stock (in shares)	503,408	503,408
Stock held by deferred compensation plan (in shares)	25,437	25,437