Note 20 - Parent Company Financial Statements (Details) - Condensed Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows From Operating Activities
Net income	$ 16,459	$ 13,446	$ 12,149
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax expense (benefit)	3,931	(473)	(1,043)
Net cash provided by operating activities	29,011	24,023	28,410
Cash Flows From Investing Activities
Net cash provided by (used in) investing activities	57,254	(53,286)	63,174
Cash Flows From Financing Activities
Redemption of preferred stock	(20,000)	0	0
Repurchase of common stock warrant	0	0	(75)
Shares issued under employee stock purchase plan	129	133	128
Net cash used in financing activities	(53,604)	1,661	(90,038)
Net (decrease) increase in cash and cash equivalents	32,661	(27,602)	1,546
Cash and cash equivalents at beginning of year	68,253	95,855	94,309
Cash and cash equivalents at end of year	100,914	68,253	95,855
Bank Subsidiaries [Member] | Parent Company [Member]
Cash Flows From Investing Activities
Investment in bank subsidiaries	0	0	(2,500)
Employee Stock Purchase Plan Expense [Member] | Parent Company [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Noncash compensation expense	4	4	3
Employee Stock Purchase Plan Expense [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Noncash compensation expense	32	36	36
Director Fee Compensation [Member] | Parent Company [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Noncash compensation expense	82	0	0
Director Fee Compensation [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Noncash compensation expense	82	0	0
Parent Company [Member]
Cash Flows From Operating Activities
Net income	16,459	13,446	12,149
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed (income) loss of subsidiaries	(1,040)	473	(1,637)
Change in other assets and liabilities, net	454	(799)	(590)
Deferred income tax expense (benefit)	17	(62)	(64)
Net cash provided by operating activities	15,976	13,062	9,861
Cash Flows From Investing Activities
Return of equity from nonbank subsidiary	1,500	0	500
Net cash provided by (used in) investing activities	1,500	0	(2,000)
Cash Flows From Financing Activities
Redemption of preferred stock	(20,000)	0	0
Dividends paid, preferred stock	(1,990)	(1,500)	(1,500)
Repurchase of common stock warrant	0	0	(75)
Shares issued under employee stock purchase plan	129	133	128
Net cash used in financing activities	(21,861)	(1,367)	(1,447)
Net (decrease) increase in cash and cash equivalents	(4,385)	11,695	6,414
Cash and cash equivalents at beginning of year	36,471	24,776	18,362
Cash and cash equivalents at end of year	$ 32,086	$ 36,471	$ 24,776