Note 7 - Fair Value Measurements - Level 3 Fair Value Measurements (Details)		3 Months Ended	12 Months Ended
		Mar. 31, 2017	Dec. 31, 2016
Impaired loans [Member] | Present Value of Cash Flows [Member] | Minimum [Member]
Discount rate		6.75%	6.75%
Impaired loans [Member] | Present Value of Cash Flows [Member] | Maximum [Member]
Discount rate		8.00%	8.00%
Impaired loans [Member] | Present Value of Cash Flows [Member] | Weighted Average [Member]
Discount rate		7.35%	7.35%
Other Real Estate Owned [Member] | Discounted Appraised Value [Member] | Minimum [Member]
Discount rate		0.00%	0.00%
Selling cost	[1]	2.91%	2.91%
Other Real Estate Owned [Member] | Discounted Appraised Value [Member] | Maximum [Member]
Discount rate		53.46%	53.46%
Selling cost		8.60%	8.60%
Other Real Estate Owned [Member] | Discounted Appraised Value [Member] | Weighted Average [Member]
Discount rate		8.58%	13.66%
Selling cost		4.93%	6.48%

[1] The Company markets other real estate owned both independently and with local realtors. Properties marketed by realtors are discounted by selling costs. Properties that the Company markets independently are not discounted by selling costs.