Derivative Instruments and Hedging Activities - Amount of Gain or Loss Recognized in Income on Derivatives (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative (Loss)/Gain	$ 1,447	$ (116)	$ 230
Interest Rate Swap Contracts—Commercial Loans
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative (Loss)/Gain	(746)	(132)	145
Interest Rate Lock Commitments—Mortgage Loans
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative (Loss)/Gain	1,715	70	25
Forward Sale Contracts—Mortgage Loans
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivative (Loss)/Gain	$ 478	$ (54)	$ 60