Note 17 - Employee Benefit Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Minimum Number of Years Allowed to Participate in Employee Stock Ownership Plan	2 years
Stock Issued During Period, Shares, Employee Stock Ownership Plan	19,377	18,012	11,887
Stock Issued During Period, Value, Employee Stock Ownership Plan	$ 600,000	$ 541,000	$ 301,902
Employee Stock Ownership Plan (ESOP), Shares Contributed to ESOP	103,367	107,202	73,439
Employee Stock Ownership Plan (ESOP), Shares in ESOP	918,360
Percentage of Outstanding Common Stock under Employee Stock Ownership Plan	1.20%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	75.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 2,100,000	$ 2,000,000	$ 1,400,000
Percentage of Participant Borrowing Capacity of Vested Amount	50.00%
Maximum [Member]
Employee Stock Ownership Plan (ESOP), Debt Structure, Direct Loan, Employer Cash Payments Used for Debt Service	$ 50,000
Minimum [Member]
Employee Stock Ownership Plan (ESOP), Debt Structure, Direct Loan, Employer Cash Payments Used for Debt Service	$ 1,000
Less than Two Years of Service [Member]
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	0.00%
Yearly after Two Years of Service [Member]
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	25.00%
Matched at 100 Percent [Member]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	4.00%