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)

v3.19.2
Note 11 - Fair Value Measurement - Financial Assets and Financial Liabilities Carried at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Available-for-sale securities $ 657,971 $ 590,184
US Treasury and Government [Member]    
Available-for-sale securities 74,707 76,993
Collateralized Mortgage Backed Securities [Member]    
Available-for-sale securities 363,425 304,304
US States and Political Subdivisions Debt Securities [Member]    
Available-for-sale securities 84,311 105,994
Corporate Debt Securities [Member]    
Available-for-sale securities 135,528 102,893
Fair Value, Recurring [Member]    
Available-for-sale securities 657,971 590,184
Fair Value, Recurring [Member] | US Treasury and Government [Member]    
Available-for-sale securities 74,707 76,993
Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Available-for-sale securities 363,425 304,304
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available-for-sale securities 84,311 105,994
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available-for-sale securities 135,528 102,893
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]    
Available-for-sale securities 651,376 583,666
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]    
Available-for-sale securities 74,707 76,993
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Available-for-sale securities 363,425 304,304
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available-for-sale securities 84,311 105,994
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available-for-sale securities 128,933 96,375
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]    
Available-for-sale securities 6,595 6,518
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]    
Available-for-sale securities 0 0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]    
Available-for-sale securities $ 6,595 $ 6,518