Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENTS (Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details)

v3.20.1
FAIR VALUE MEASUREMENTS (Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
ASSETS    
Securities available for sale, at fair value $ 1,972,903 $ 1,945,445
Loans held for sale, at fair value 76,690 55,405
Fair value hedges 1 182
LIABILITIES    
Cash flow hedges   1,147
Fair value hedges 14,769 6,256
Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Securities available for sale, at fair value 0 0
Loans held for sale, at fair value 0 0
Fair value hedges 0 0
LIABILITIES    
Cash flow hedges   0
Fair value hedges 0 0
Significant Other Observable Inputs Level 2    
ASSETS    
Securities available for sale, at fair value 1,972,903 1,945,445
Loans held for sale, at fair value 76,690 55,405
Fair value hedges 1 182
LIABILITIES    
Cash flow hedges   1,147
Fair value hedges 14,769 6,256
Significant Unobservable Inputs Level 3    
ASSETS    
Securities available for sale, at fair value 0 0
Loans held for sale, at fair value 0 0
Fair value hedges 0 0
LIABILITIES    
Cash flow hedges   0
Fair value hedges 0 0
Recurring    
ASSETS    
Loans held for sale, at fair value 76,690 55,405
Fair value hedges 1 182
LIABILITIES    
Cash flow hedges   1,147
Fair value hedges 14,769 6,256
Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Loans held for sale, at fair value 0 0
Fair value hedges 0 0
LIABILITIES    
Cash flow hedges   0
Fair value hedges 0 0
Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Loans held for sale, at fair value 76,690 55,405
Fair value hedges 1 182
LIABILITIES    
Cash flow hedges   1,147
Fair value hedges 14,769 6,256
Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Loans held for sale, at fair value 0 0
Fair value hedges 0 0
LIABILITIES    
Cash flow hedges   0
Fair value hedges 0 0
U.S. government and agency securities    
ASSETS    
Securities available for sale, at fair value 17,962 21,320
U.S. government and agency securities | Recurring    
ASSETS    
Securities available for sale, at fair value 17,962 21,320
U.S. government and agency securities | Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Securities available for sale, at fair value 0  
U.S. government and agency securities | Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Securities available for sale, at fair value 17,962 21,320
U.S. government and agency securities | Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Securities available for sale, at fair value 0  
Obligations of states and political subdivisions    
ASSETS    
Securities available for sale, at fair value 546,726 447,091
Obligations of states and political subdivisions | Recurring    
ASSETS    
Securities available for sale, at fair value 546,726 447,091
Obligations of states and political subdivisions | Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Securities available for sale, at fair value 0 0
Obligations of states and political subdivisions | Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Securities available for sale, at fair value 546,726 447,091
Obligations of states and political subdivisions | Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Securities available for sale, at fair value 0 0
Corporate and other bonds    
ASSETS    
Securities available for sale, at fair value 120,968 135,959
Corporate and other bonds | Recurring    
ASSETS    
Securities available for sale, at fair value 120,968 135,959
Corporate and other bonds | Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Securities available for sale, at fair value 0 0
Corporate and other bonds | Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Securities available for sale, at fair value 120,968 135,959
Corporate and other bonds | Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Securities available for sale, at fair value 0 0
Total mortgage-back securities    
ASSETS    
Securities available for sale, at fair value 1,284,157 1,337,996
Total mortgage-back securities | Recurring    
ASSETS    
Securities available for sale, at fair value 1,284,157 1,337,996
Total mortgage-back securities | Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Securities available for sale, at fair value 0 0
Total mortgage-back securities | Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Securities available for sale, at fair value 1,284,157 1,337,996
Total mortgage-back securities | Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Securities available for sale, at fair value 0 0
Other securities    
ASSETS    
Securities available for sale, at fair value 3,090 3,079
Other securities | Recurring    
ASSETS    
Securities available for sale, at fair value 3,090 3,079
Other securities | Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Securities available for sale, at fair value 0 0
Other securities | Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Securities available for sale, at fair value 3,090 3,079
Other securities | Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Securities available for sale, at fair value 0 0
Interest Rate Swap    
ASSETS    
Interest rate swap 174,704 54,345
LIABILITIES    
Interest rate swap 174,704 54,345
Interest Rate Swap | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Interest rate swap 0 0
LIABILITIES    
Interest rate swap 0 0
Interest Rate Swap | Significant Other Observable Inputs Level 2    
ASSETS    
Interest rate swap 174,704 54,345
LIABILITIES    
Interest rate swap 174,704 54,345
Interest Rate Swap | Significant Unobservable Inputs Level 3    
ASSETS    
Interest rate swap 0 0
LIABILITIES    
Interest rate swap 0 0
Interest Rate Swap | Recurring    
ASSETS    
Interest rate swap 174,704 54,345
LIABILITIES    
Interest rate swap 174,704 54,345
Interest Rate Swap | Recurring | Quoted Prices in Active Markets for Identical Assets Level 1    
ASSETS    
Interest rate swap 0 0
LIABILITIES    
Interest rate swap 0 0
Interest Rate Swap | Recurring | Significant Other Observable Inputs Level 2    
ASSETS    
Interest rate swap 174,704 54,345
LIABILITIES    
Interest rate swap 174,704 54,345
Interest Rate Swap | Recurring | Significant Unobservable Inputs Level 3    
ASSETS    
Interest rate swap 0 0
LIABILITIES    
Interest rate swap $ 0 $ 0