Note 20 - Parent Company Financial Statements (Details) - Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities
Net income	$ 3,584	$ 3,832	$ 3,502	$ 4,074	$ 4,158	$ 4,107	$ 4,824	$ 3,370	$ 14,992	$ 16,459	$ 13,446
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax (benefit) expense									1,631	3,931	(473)
Net cash provided by operating activities									25,930	29,011	24,023
Cash Flows From Investing Activities
Net cash provided by investing activities									15,875	57,254	(53,286)
Cash Flows From Financing Activities
Shares issued under employee stock purchase plan									130	129	133
Net cash used in financing activities									(22,226)	(53,604)	1,661
Net increase (decrease) in cash and cash equivalents									19,579	32,661	(27,602)
Cash and cash equivalents at beginning of year				100,914				68,253	100,914	68,253	95,855
Cash and cash equivalents at end of year	120,493				100,914				120,493	100,914	68,253
Employee Stock Purchase Plan Expense [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Share Based Compensation									31	32	36
Director Fee Compensation [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Share Based Compensation									104	82	0
Parent Company [Member]
Cash Flows From Operating Activities
Net income									14,992	16,459	13,446
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed (income) loss of subsidiaries									(2,727)	(1,040)	473
Change in other assets and liabilities, net									582	454	(799)
Deferred income tax (benefit) expense									(54)	17	(62)
Net cash provided by operating activities									12,901	15,976	13,062
Cash Flows From Investing Activities
Return of equity from nonbank subsidiary									1,355	1,500	0
Net cash provided by investing activities									1,355	1,500	0
Cash Flows From Financing Activities
Redemption of preferred stock									(10,000)	(20,000)	0
Dividends paid, preferred stock									(508)	(1,990)	(1,500)
Shares issued under employee stock purchase plan									130	129	133
Net cash used in financing activities									(10,378)	(21,861)	(1,367)
Net increase (decrease) in cash and cash equivalents									3,878	(4,385)	11,695
Cash and cash equivalents at beginning of year				$ 32,086				$ 36,471	32,086	36,471	24,776
Cash and cash equivalents at end of year	$ 35,964				$ 32,086				35,964	32,086	36,471
Parent Company [Member] | Employee Stock Purchase Plan Expense [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Share Based Compensation									4	4	4
Parent Company [Member] | Director Fee Compensation [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Share Based Compensation									$ 104	$ 82	$ 0