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)

v3.20.1
Note 11 - Fair Value Measurement - Financial Assets and Financial Liabilities Carried at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Debt Securities, Available-for-sale, Total $ 826,782 $ 759,399 [1]
US Treasury Securities [Member]    
Debt Securities, Available-for-sale, Total 49,782 49,210
US Government Agencies Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 18,593 18,386
Collateralized Mortgage Backed Securities [Member]    
Debt Securities, Available-for-sale, Total 546,431 474,054
US States and Political Subdivisions Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 51,328 57,272
Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 160,648 160,477
Fair Value, Recurring [Member]    
Debt Securities, Available-for-sale, Total 826,782 759,399
Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Debt Securities, Available-for-sale, Total 49,782 49,210
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 18,593 18,386
Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Debt Securities, Available-for-sale, Total 546,431 474,054
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 51,328 57,272
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 160,648 160,477
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]    
Debt Securities, Available-for-sale, Total 820,135 752,803
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Debt Securities, Available-for-sale, Total 49,782 49,210
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 18,593 18,386
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Debt Securities, Available-for-sale, Total 546,431 474,054
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 51,328 57,272
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 154,001 153,881
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]    
Debt Securities, Available-for-sale, Total 6,647 6,596
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Debt Securities, Available-for-sale, Total 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale, Total $ 6,647 $ 6,596
[1] derived from audited financial statements.