Derivative Financial Instruments (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Interest rate swaps [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	$ 360,000	$ 60,000
Interest rate swaps with customers [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	998,530	991,002
Mirror swaps with counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	998,530	991,002
Risk participation-in agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	147,404	92,717
Interest rate lock commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	97,856	167,671
Forward sale commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	195,105	279,653
Derivatives Designated as Cash Flow Hedging Instruments [Member] | Interest rate swaps [Member] | Commercial Loan
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	300,000
Derivatives Designated as Cash Flow Hedging Instruments [Member] | Interest rate swaps [Member] | Federal Home Loan Bank Advances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	60,000	60,000
Not Designated as Hedging Instrument [Member] | Interest rate swaps with customers [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	998,500	991,000
Not Designated as Hedging Instrument [Member] | Mirror swaps with counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	998,500	991,000
Not Designated as Hedging Instrument [Member] | Risk participation-out agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	74,600	61,600
Not Designated as Hedging Instrument [Member] | Risk participation-in agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	$ 147,400	$ 92,700