Derivatives - Derivative Assets And Collateral Received (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Gross amounts of recognized assets	$ 183,115	$ 81,475
Derivative assets not subject to master netting agreements	20,800	28,900
Derivatives, interest rate contracts
Derivative [Line Items]
Gross amounts of recognized assets	162,344	52,562
Gross amounts offset in the Statements of Condition	0	0
Net amounts of assets presented in the Statements of Condition	162,344	52,562
Gross amounts not offset in the Statements of Condition, Derivative liabilities available for offset	(5,604)	(12,745)
Collateral Received	(143,334)	(39,637)
Net amount	$ 13,406	$ 180