Note 19 - Parent Company Financial Information - Statements of Cash Flows (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income (loss)	$ 4,101,000	$ (967,000)	$ 2,512,000	$ (593,000)	$ (2,485,000)	$ (1,822,000)	$ 381,000	$ 426,000	$ 5,054,000	$ (3,500,000)	$ 8,627,000
Share based compensation									1,918,000	2,632,000	2,116,000
Amortization of debt issuance costs									6,000	6,000	6,000
Net cash used in operating activities									(10,729,000)	19,333,000	39,630,000
Net cash used in investing activities									(1,078,205,000)	(438,622,000)	(450,763,000)
Net proceeds from issuance of preferred stock									48,325,000	0	0
Preferred share dividends									923,000	(0)	(0)
Return of short swing profit									18,000	0	0
Net proceeds from exercise of stock options									41,305	261,143	670,413
Net cash provided by financing activities									1,695,915,000	515,135,000	421,664,000
Increase (decrease) in cash									606,981,000	95,846,000	10,531,000
Cash and cash equivalents, beginning of year				168,319,000				72,473,000	168,319,000	72,473,000	61,942,000
Cash and cash equivalents, end of year	775,300,000				168,319,000				775,300,000	168,319,000	72,473,000
Parent Company [Member]
Net income (loss)									5,054,000	(3,500,000)	8,627,000
Share based compensation									1,918,000	2,632,000	2,116,000
Amortization of debt issuance costs									6,000	6,000	6,000
Increase in other assets									(707,000)	(1,069,000)	(1,639,000)
Net increase (decrease) in other liabilities									257,000	(18,000)	20,000
Equity in undistributed income of subsidiaries									(7,444,000)	293,000	(12,387,000)
Net cash used in operating activities									(916,000)	(1,656,000)	(3,257,000)
Investment in subsidiary									(30,000,000)	(20,000,000)	(30,000,000)
Net cash used in investing activities									(30,000,000)	(20,000,000)	(30,000,000)
Net proceeds from issuance of preferred stock									48,325,000
Preferred share dividends									(923,000)
Return of short swing profit									18,000
Net proceeds from exercise of stock options									41,000	261,000	670,000
Net cash provided by financing activities									47,461,000	261,000	670,000
Increase (decrease) in cash									16,545,000	(21,395,000)	(32,587,000)
Cash and cash equivalents, beginning of year				$ 6,327,000				$ 27,722,000	6,327,000	27,722,000	60,309,000
Cash and cash equivalents, end of year	$ 22,872,000				$ 6,327,000				$ 22,872,000	$ 6,327,000	$ 27,722,000