Derivative Instruments - Amounts and Locations of Activity Related to Interest Rate Swaps Designated as Cash Flow Hedges within Corporation's Consolidated Balance Sheet and Statement of Income (Details) - Interest Rate Swaps - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Derivative [Line Items]
Interest rate contracts	$ 84	$ (329)
Accrued interest and other liabilities
Derivative [Line Items]
Accrued interest and other liabilities	(662)		$ (768)
Interest expense – subordinated debentures
Derivative [Line Items]
Other income	(69)	(21)
Other income
Derivative [Line Items]
Other income	$ 0	$ 0