Note 13 - Stockholders' Equity (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Treasury Stock, Shares, Acquired	403,695	735,599
Treasury Stock Acquired, Average Cost Per Share	$ 19.89	$ 19.51
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 495,905
Available to Distribute to the Holding Company as Cash Dividends [Member]
Retained Earnings, Unappropriated	91,200,000
Savings Bank [Member]
Liquidation Account, Conversion From Mutual to Stock Form	$ 700,000