Derivatives and Hedging Activities (Customer Related Derivative Positions - Not Designated as Hedges) (Details) - Not Designated as Hedging Instrument $ in Thousands		Sep. 30, 2020 USD ($) position	Dec. 31, 2019 USD ($) position
Receive fixed, pay variable | Loan level swaps
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	331	299
Less than 1 year		$ 135,993	$ 156,690
Less than 2 years		34,017	125,203
Less than 3 years		158,477	85,603
Less than 4 years		138,314	165,599
Thereafter		1,260,159	1,044,315
Derivative, Notional Amount		1,726,960	1,577,410
Fair Value	[2]	$ 145,517	$ 48,596
Pay fixed, receive variable | Loan level swaps
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	322	290
Less than 1 year		$ 135,993	$ 156,690
Less than 2 years		34,017	125,203
Less than 3 years		158,477	85,603
Less than 4 years		138,314	165,599
Thereafter		1,260,159	1,044,315
Derivative, Notional Amount		1,726,960	1,577,410
Fair Value	[2]	$ (145,501)	$ (48,591)
Buys foreign currency, sells U.S. currency | Foreign exchange contracts
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	33	40
Less than 1 year		$ 81,207	$ 91,434
Derivative, Notional Amount		81,207	91,434
Fair Value	[2]	$ (3,125)	$ (81)
Buys U.S. currency, sells foreign currency | Foreign exchange contracts
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	33	40
Less than 1 year		$ 81,207	$ 91,434
Derivative, Notional Amount		81,207	91,434
Fair Value	[2]	$ 3,151	$ 123
Risk Participated Out | Risk Participation Agreement
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position		13
Less than 1 year		$ 6,800
Less than 3 years		7,282
Thereafter		112,487
Derivative, Notional Amount		126,569
Fair Value		$ 745
Risk Participated In | Risk Participation Agreement
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position		10
Less than 2 years		$ 18,978
Less than 3 years		23,925
Less than 4 years		36,836
Thereafter		18,295
Derivative, Notional Amount		98,034
Fair Value		$ (269)

[1] The Company may enter into one dealer swap agreement which offsets multiple commercial borrower swap agreements.

[2] Beginning in 2020, the Company made an election to include accrued interest within fair value balances.