Note 4 - Loans/Leases Receivable (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) loan lease	Dec. 31, 2021 USD ($) loan lease	Dec. 31, 2020 USD ($)	Jan. 01, 2021 USD ($)	Dec. 31, 2019 USD ($)
Loan	$ 6,138,871,000	$ 4,680,132,000
Accrued interest on loans	24,300,000	15,300,000
Nonaccrual Loans/Leases	8,765,000	2,759,000
Accruing Past Due 90 Days or More		1,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	232,000	2,599,000
Less allowance for estimated losses on loans/leases	87,706,000	78,721,000	$ 84,376,000	$ 84,376,000	$ 36,001,000
Provision for Loan and Lease Losses	9,636,000	5,702,000	55,704,000
Allowance for Loan and Lease Losses, Write-offs	7,525,000	4,538,000	8,383,000
Recoveries on loans/leases previously charged off	972,000	1,283,000	1,054,000
Threshold for Related Party Loans Evaluated	60,000	60,000	60,000
Interest income on nonaccrual loans	$ 331,000,000	$ 494,000,000
Number of Loans / Leases | loan	3	3
Nonaccrual [Member]
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 54,000
Number of Loans / Leases		1
Guaranty Bank
Provision for Loan and Lease Losses	11,000,000.0
Residential real estate
Residential real estate loan held for sale	1,500,000	$ 3,800,000
Less allowance for estimated losses on loans/leases			3,732,000	3,732,000	1,948,000
Provision for Loan and Lease Losses			1,755,000
Recoveries on loans/leases previously charged off			29,000
Commercial Portfolio Segment [Member]
Loan	1,748,562,000	1,595,085,000
Less allowance for estimated losses on loans/leases			35,421,000	35,421,000	16,072,000
Provision for Loan and Lease Losses			22,899,000
Allowance for Loan and Lease Losses, Write-offs			4,199,000
Recoveries on loans/leases previously charged off			649,000
Commercial Portfolio Segment [Member] | C&I - other
Loan	1,451,693,000	1,346,602,000
Nonaccrual Loans/Leases	3,135,000	1,400,000
Accruing Past Due 90 Days or More		1,000
Less allowance for estimated losses on loans/leases	27,753,000	25,982,000
Provision for Loan and Lease Losses	7,364,000	(1,451,000)
Allowance for Loan and Lease Losses, Write-offs	6,417,000	2,287,000
Recoveries on loans/leases previously charged off	817,000	590,000
Commercial Portfolio Segment [Member] | m2 Lease Funds, LLC
Loan	$ 278,000,000.0	$ 225,100,000
Commercial Real Estate Portfolio Segment [Member]
Less allowance for estimated losses on loans/leases			42,161,000	42,161,000	15,379,000
Provision for Loan and Lease Losses			28,671,000
Allowance for Loan and Lease Losses, Write-offs			2,071,000
Recoveries on loans/leases previously charged off			182,000
Direct financing leases
Number of Leases | lease	2	2
Loss related to unguaranteed residual values of leases	$ 0	$ 0	0
Loan	31,889,000	45,191,000
Nonaccrual Loans/Leases	135,000	847,000
Less allowance for estimated losses on loans/leases	970,000	1,546,000	1,764,000	1,764,000	1,464,000
Provision for Loan and Lease Losses			2,148,000
Allowance for Loan and Lease Losses, Write-offs			1,993,000
Recoveries on loans/leases previously charged off			145,000
Direct financing leases | PPP loans
Loan	68,300,000	28,200,000
Direct financing leases | C&I - other
Less allowance for estimated losses on loans/leases	1,500,000		1,800,000
Provision for Loan and Lease Losses	(269,000)
Allowance for Loan and Lease Losses, Write-offs	1,100,000
Recoveries on loans/leases previously charged off	273,000
Threshold for Related Party Loans Evaluated	970,000,000
Consumer
Loan	110,421,000	75,311,000
Nonaccrual Loans/Leases	353,000	31,000
Less allowance for estimated losses on loans/leases	1,371,000	930,000	1,298,000	$ 1,298,000
Provision for Loan and Lease Losses	477,000	(509,000)
Allowance for Loan and Lease Losses, Write-offs	65,000	46,000
Recoveries on loans/leases previously charged off	9,000	324,000
Installment and other consumer loans
Less allowance for estimated losses on loans/leases			1,298,000		$ 1,138,000
Provision for Loan and Lease Losses			231,000
Allowance for Loan and Lease Losses, Write-offs			120,000
Recoveries on loans/leases previously charged off			$ 49,000
No Lease End Option Rider [Member] | Direct financing leases
Lease residual values	$ 165,000	$ 165,000