Note 15 - Comprehensive Income - Reclassification out of Accumulated Other Comprehensive (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net gains on sale of securities available-for-sale									$ 0	$ 195	$ 29
Income tax benefit	$ 12,348	$ 10,425	$ 11,889	$ 11,351	$ 12,301	$ 10,881	$ 10,652	$ 10,871	46,013	44,705	19,101
Net income	32,557	28,915	32,358	31,381	33,038	32,097	32,219	32,999	125,211	130,353	71,289
Net interest income (expense) on swaps	$ 34,460	$ 18,819	$ 9,765	$ 8,583	$ 8,579	$ 8,781	$ 10,042	$ 11,458	71,627	38,860	70,209
Salaries and employee benefits									81,289	64,341	58,877
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net income									2,221	(1,413)	(1,328)
Reclassification out of Accumulated Other Comprehensive Income [Member] | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Net gains on sale of securities available-for-sale									0	195	29
Income tax benefit									0	(48)	(6)
Net income									0	147	23
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Income tax benefit									(976)	528	443
Net income									2,267	(1,345)	(1,134)
Net interest income (expense) on swaps									3,243	(1,873)	(1,577)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Income tax benefit									20	84	84
Net income									(46)	(215)	(217)
Salaries and employee benefits									$ (66)	$ (299)	$ (301)