Derivatives, Hedging Activities, and Other Financial Instruments - Notional and Fair Value of Derivatives Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other assets
Derivative [Line Items]
Credit risk derivative asset, fair value	$ 27,503	$ 45,289
Other liabilities
Derivative [Line Items]
Credit risk derivative liability, fair value	$ 27,589	$ 45,429