Derivatives, Hedging Activities, and Other Financial Instruments - Notional and Fair Value of Derivatives Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Other assets
Derivative [Line Items]
Credit risk derivative asset, fair value	$ 55,516	$ 10,141
Other liabilities
Derivative [Line Items]
Credit risk derivative liability, fair value	$ 55,719	$ 10,708