Commitments and Contingencies (Financial Instruments with Off Balance Sheet Risk) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Interest rate lock commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	$ 84,820	$ 30,766
Forward sale commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	156,594	61,993
Interest rate swaps with customers [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	729,913	648,050
Mirror swaps with counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	729,913	648,050
Risk participation-in agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	73,040	46,510
Foreign exchange contracts [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	2,648	2,784
Interest rate swaps [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	60,000	60,000
Commitments to extend credit on commerical loans [Member] | Commitments to extend credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	481,350	533,884
Commitments to extend credit on home equity lines [Member] | Commitments to extend credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	290,442	270,462
Commitments to extend credit on other loans [Member] | Commitments to extend credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	74,931	46,698
Commitments to extend credit on standby letters of credit [Member] | Commitments to extend credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount	$ 9,343	$ 7,706