Derivative Financial Instruments Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Offsetting Assets [Line Items]
Derivative asset, fair value	$ 375,909	$ 144,371
Derivative, Collateral, Obligation to Return Securities	21	802
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	375,888	143,569
Derivative liability, gross liability	183,249	76,067
Derivative liability, Collateral, Right to Reclaim Securities	(21)	(802)
Derivative liability, Collateral, Right to Reclaim Cash	(183,228)	(75,265)
Derivative liability, Net Amount	0	0
Interest Rate Swap [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	375,569	144,179
Derivative, Collateral, Obligation to Return Securities	2	757
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	375,567	143,422
Derivative liability, gross liability	183,230	76,022
Derivative liability, Collateral, Right to Reclaim Securities	(2)	(757)
Derivative liability, Collateral, Right to Reclaim Cash	(183,228)	(75,265)
Derivative liability, Net Amount	0	0
Foreign Exchange Contract [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	340	192
Derivative, Collateral, Obligation to Return Securities	19	45
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	321	147
Derivative liability, gross liability	19	45
Derivative liability, Collateral, Right to Reclaim Securities	(19)	(45)
Derivative liability, Collateral, Right to Reclaim Cash	0	0
Derivative liability, Net Amount	$ 0	$ 0