Derivative Instruments and Hedge Activities - Summary of Company's Interest Rate Derivative and Offsetting Positions (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Gross amounts recognized	$ 19,133	$ 7,960
Net amount presented in the Consolidated Statements of Financial Condition	19,133	7,960
Gross amounts not offset in the Consolidated Statements of Financial Condition
Offsetting derivative positions		(1)
Collateral posted	(19,133)	(7,959)
Gross amounts recognized	20,327	8,519
Net amount presented in the Consolidated Statements of Financial Condition	20,327	8,519
Gross amounts not offset in the Consolidated Statements of Financial Condition
Offsetting derivative positions		(1)
Collateral posted	$ (20,327)	$ (8,518)