Quarterly report pursuant to Section 13 or 15(d)

Note 11 - Fair Value Measurement - Financial Assets and Financial Liabilities Carried at Fair Value on a Recurring Basis (Details)

v3.24.3
Note 11 - Fair Value Measurement - Financial Assets and Financial Liabilities Carried at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Sep. 30, 2024
Dec. 31, 2023
Available for sale, fair value $ 1,139,007 $ 900,183 [1]
US Treasury Securities [Member]    
Available for sale, fair value 567,324 340,807
Collateralized Mortgage-Backed Securities [Member]    
Available for sale, fair value 238,300 215,485
US States and Political Subdivisions Debt Securities [Member]    
Available for sale, fair value 9,718 10,223
Corporate Debt Securities [Member]    
Available for sale, fair value 323,665 333,667
Fair Value, Recurring [Member]    
Available for sale, fair value 1,139,007 900,183
Total assets at fair value 1,139,007 900,183
Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Available for sale, fair value 567,324 340,807
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Available for sale, fair value   0
Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member]    
Available for sale, fair value 238,300 215,485
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available for sale, fair value 9,718 10,223
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available for sale, fair value 323,665 333,668
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]    
Available for sale, fair value 567,324 340,807
Total assets at fair value 567,324 340,807
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Available for sale, fair value 567,324 340,807
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Available for sale, fair value   0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]    
Available for sale, fair value 571,683 552,516
Total assets at fair value 571,683 552,516
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Available for sale, fair value   0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member]    
Available for sale, fair value 238,300 215,485
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available for sale, fair value 9,718 10,223
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available for sale, fair value 323,665 326,808
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]    
Available for sale, fair value 0 6,860
Total assets at fair value 0 6,860
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Available for sale, fair value   0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage-Backed Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available for sale, fair value 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available for sale, fair value $ 0 $ 6,860
[1] Derived from audited financial statements.