Note 20 - Segments - Financial Information by Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Net interest income	$ 45,483			$ 33,695			$ 124,892	$ 99,669
Provision for credit losses	(1,525)			4,968			1,147	17,918
All other non-interest income	10,486			7,386			27,012	20,600
Non-interest expenses	34,558			25,646			107,708	72,630
Income before income tax expense	30,064			16,124			63,283	47,322
Income tax expense	6,902			1,591			13,227	6,189
Net income	23,162	$ 4,184	$ 22,710	14,533	$ 13,368	$ 13,232	50,056	41,133
Segment assets	6,181,188			4,365,129			6,181,188	4,365,129	$ 4,608,629
Fiduciary and Trust [Member]
Wealth management and trust services	7,128			5,657			20,234	17,601
Commercial Banking [Member]
Net interest income	45,414			33,619			124,672	99,423
Provision for credit losses	(1,525)			4,968			1,147	17,918
All other non-interest income	10,486			7,386			27,012	20,600
Non-interest expenses	31,072			22,512			97,249	63,063
Income before income tax expense	26,353			13,525			53,288	39,042
Income tax expense	6,070			1,027			11,058	4,392
Net income	20,283			12,498			42,230	34,650
Segment assets	6,177,355			4,361,576			6,177,355	4,361,576
Commercial Banking [Member] | Fiduciary and Trust [Member]
Wealth management and trust services	0			0			0	0
Investment Management and Trust [Member]
Net interest income	69			76			220	246
Provision for credit losses	0			0			0	0
All other non-interest income	0			0			0	0
Non-interest expenses	3,486			3,134			10,459	9,567
Income before income tax expense	3,711			2,599			9,995	8,280
Income tax expense	832			564			2,169	1,797
Net income	2,879			2,035			7,826	6,483
Segment assets	3,833			3,553			3,833	3,553
Investment Management and Trust [Member] | Fiduciary and Trust [Member]
Wealth management and trust services	$ 7,128			$ 5,657			$ 20,234	$ 17,601