Note 20 - Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure
Total interest income	$ 52,977	$ 56,817	$ 54,181	$ 52,101	$ 52,704	$ 49,830	$ 40,799	$ 39,546
Total interest expense	13,058	16,098	16,168	15,193	13,109	11,516	8,714	7,143	$ 60,517	$ 40,484	$ 19,452
Net interest income	39,919	40,719	38,013	36,908	39,595	38,314	32,085	32,403	155,559	142,395	116,065
Provision for loan/lease losses	979	2,012	1,941	2,134	1,612	6,206	2,301	2,540	7,066	12,658	8,470
Noninterest income	29,805	19,906	17,065	11,992	15,278	8,809	8,912	8,541	78,768	41,541	30,482
Noninterest expense	46,294	39,945	36,560	32,435	36,410	30,500	26,370	25,863	155,234	119,143	97,424
Income before taxes	22,451	18,668	16,577	14,331	16,851	10,417	12,326	12,541	72,027	52,135	40,653
Federal and state income tax expense (benefit)	6,560	3,573	3,073	1,413	3,535	1,608	1,881	1,991	14,619	9,015	4,946
Net income	$ 15,891	$ 15,095	$ 13,504	$ 12,918	$ 13,316	$ 8,809	$ 10,445	$ 10,550	$ 57,408	$ 43,120	$ 35,707
Basic (in dollars per share)	$ 1.01	$ 0.96	$ 0.86	$ 0.82	$ 0.85	$ 0.56	$ 0.75	$ 0.76	$ 3.65	$ 2.92	$ 2.68
Diluted (in dollars per share)	$ 0.99	$ 0.94	$ 0.85	$ 0.81	$ 0.84	$ 0.55	$ 0.73	$ 0.74	$ 3.60	$ 2.86	$ 2.61