Derivatives and Hedging Activities (Customer Related Derivative Positions) (Details)
Mar. 31, 2020
USD ($)
derivative
Dec. 31, 2019
USD ($)
derivative
Derivatives and Hedging Activities    
Collateral posted $ 155,200,000 $ 86,500,000
Collateral posted, dealer counterparties 0 0
Receive fixed, pay variable    
Derivatives and Hedging Activities    
Total $ 1,231,096,000 $ 1,101,193,000
Receive fixed, pay variable | Derivatives not designed as hedging instruments    
Derivatives and Hedging Activities    
Number of Positions | derivative 129,000 119,000
Notional Amount Maturing, Less than 1 year $ 24,358,000 $ 24,777,000
Notional Amount Maturing, Less than 2 years 0 0
Notional Amount Maturing, Less than 3 years 33,455,000 31,131,000
Notional Amount Maturing, Less than 4 years 14,220,000 16,794,000
Notional Amount Maturing, Thereafter 1,159,063,000 1,028,491,000
Total 1,231,096,000 1,101,193,000
Fair Value 154,032,000 58,102,000
Pay fixed, receive variable    
Derivatives and Hedging Activities    
Total $ 1,231,096,000 $ 1,101,193,000
Pay fixed, receive variable | Derivatives not designed as hedging instruments    
Derivatives and Hedging Activities    
Number of Positions | derivative 129,000 119,000
Notional Amount Maturing, Less than 1 year $ 24,358,000 $ 24,777,000
Notional Amount Maturing, Less than 2 years 0 0
Notional Amount Maturing, Less than 3 years 33,455,000 31,131,000
Notional Amount Maturing, Less than 4 years 14,220,000 16,794,000
Notional Amount Maturing, Thereafter 1,159,063,000 1,028,491,000
Total 1,231,096,000 1,101,193,000
Fair Value 154,032,000 58,102,000
Risk participation-out agreements    
Derivatives and Hedging Activities    
Total $ 233,846,000 $ 235,693,000
Risk participation-out agreements | Derivatives not designed as hedging instruments    
Derivatives and Hedging Activities    
Number of Positions | derivative 40,000 40,000
Notional Amount Maturing, Less than 1 year $ 13,731,000 $ 13,967,000
Notional Amount Maturing, Less than 2 years 0 0
Notional Amount Maturing, Less than 3 years 7,110,000 0
Notional Amount Maturing, Less than 4 years 12,773,000 7,143,000
Notional Amount Maturing, Thereafter 200,232,000 214,583,000
Total 233,846,000 235,693,000
Fair Value 2,473,000 1,229,000
Risk participation-in agreements    
Derivatives and Hedging Activities    
Total $ 49,279,000 $ 55,281,000
Risk participation-in agreements | Derivatives not designed as hedging instruments    
Derivatives and Hedging Activities    
Number of Positions | derivative 6,000 7,000
Notional Amount Maturing, Less than 1 year $ 0 $ 0
Notional Amount Maturing, Less than 2 years 0 0
Notional Amount Maturing, Less than 3 years 0 0
Notional Amount Maturing, Less than 4 years 19,000,000 19,000,000
Notional Amount Maturing, Thereafter 30,279,000 36,281,000
Total 49,279,000 55,281,000
Fair Value 432,000 283,000
Buys foreign currency, sells U.S. currency | Foreign exchange contracts    
Derivatives and Hedging Activities    
Total $ 1,422,000 $ 1,125,000
Buys foreign currency, sells U.S. currency | Foreign exchange contracts | Derivatives not designed as hedging instruments    
Derivatives and Hedging Activities    
Number of Positions | derivative 24,000 16,000
Notional Amount Maturing, Less than 1 year $ 1,422,000 $ 1,125,000
Notional Amount Maturing, Less than 2 years 0 0
Notional Amount Maturing, Less than 3 years 0 0
Notional Amount Maturing, Less than 4 years 0 0
Notional Amount Maturing, Thereafter 0 0
Total 1,422,000 1,125,000
Fair Value 200,000 54,000
Sells foreign currency, buys U.S. currency | Foreign exchange contracts    
Derivatives and Hedging Activities    
Total $ 1,530,000 $ 1,230,000
Sells foreign currency, buys U.S. currency | Foreign exchange contracts | Derivatives not designed as hedging instruments    
Derivatives and Hedging Activities    
Number of Positions | derivative 25,000 18,000
Notional Amount Maturing, Less than 1 year $ 1,530,000 $ 1,230,000
Notional Amount Maturing, Less than 2 years 0 0
Notional Amount Maturing, Less than 3 years 0 0
Notional Amount Maturing, Less than 4 years 0 0
Notional Amount Maturing, Thereafter 0 0
Total 1,530,000 1,230,000
Fair Value $ 224,000 $ 53,000