Note 3 - Mergers and Acquisitions - (Details Textual) - USD ($)		3 Months Ended	12 Months Ended
	Mar. 01, 2022	Mar. 31, 2023	Dec. 31, 2022	Feb. 28, 2022
Assets, Total		$ 6,289,981,000	$ 5,990,460,000
Financing Receivable, after Allowance for Credit Loss, Total		4,761,230,000	4,567,998,000
Deposits, Total		$ 4,806,178,000	4,820,345,000
Core Deposits [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		10 years
Texas Citizens Bancorp [Member]
Assets, Total				$ 534,200,000
Financing Receivable, after Allowance for Credit Loss, Total				349,500,000
Deposits, Total				$ 477,200,000
Business Combination, Acquisition Related Costs		$ 103,000	$ 5,200,000
Texas Citizens Bancorp [Member]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares)	2,069,532