Note 6 - Other Assets and Other Liabilities - Other Assets (Details) - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
Cost method equity investments:
Federal Reserve Bank stock (1)	[1]	$ 14,069	$ 14,069
Other investments		158	158
Total cost method equity investments		14,227	14,227
Life insurance cash surrender value		68,056	66,611
Net deferred tax asset		100,828	99,507
Right-of-use asset		18,832	18,814
Limited partnership investments		25,787	28,667
Interest receivable		50,334	54,568
Prepaid assets		4,496	5,200
Other assets		19,203	9,716
Total other assets		$ 301,763	$ 297,310

[1] A bank applying for membership in the Federal Reserve System is required to subscribe to stock in the Federal Reserve Bank (FRB) in its district in a sum equal to six percent of the bank’s paid-up capital stock and surplus. One-half of the amount of the bank's subscription shall be paid to the FRB and the remaining half will be subject to call when deemed necessary by the Board of Governors of the Federal Reserve System.