Note 10 - Collateralized Securities Transactions - Secured Borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Securities sold under agreements to repurchase	$ 402,389	$ 400,391
Receivables under resale agreements	359,602	357,408
Overnight and Continuous [Member]
Securities sold under agreements to repurchase	42,853	43,069
Receivables under resale agreements	0	0
Maturity Less than 30 Days [Member]
Securities sold under agreements to repurchase	359,536	357,322
Receivables under resale agreements	359,602	357,408
Maturity 30 to 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Receivables under resale agreements	0	0
Maturity Greater than 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Receivables under resale agreements	0	0
Collateralized Mortgage-Backed Securities [Member]
Securities sold under agreements to repurchase	359,536	357,322
Receivables under resale agreements	359,602	357,408
Collateralized Mortgage-Backed Securities [Member] | Overnight and Continuous [Member]
Securities sold under agreements to repurchase	0	0
Receivables under resale agreements	0	0
Collateralized Mortgage-Backed Securities [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreements to repurchase	359,536	357,322
Receivables under resale agreements	359,602	357,408
Collateralized Mortgage-Backed Securities [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Receivables under resale agreements	0	0
Collateralized Mortgage-Backed Securities [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreements to repurchase	0	0
Receivables under resale agreements	0	0
SBA Loans [Member]
Securities sold under agreements to repurchase	42,853	43,069
SBA Loans [Member] | Overnight and Continuous [Member]
Securities sold under agreements to repurchase	42,853	43,069
SBA Loans [Member] | Maturity Less than 30 Days [Member]
Securities sold under agreements to repurchase	0	0
SBA Loans [Member] | Maturity 30 to 90 Days [Member]
Securities sold under agreements to repurchase	0	0
SBA Loans [Member] | Maturity Greater than 90 Days [Member]
Securities sold under agreements to repurchase	$ 0	$ 0