Derivative Financial Instruments Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Offsetting Assets [Line Items]
Derivative asset, fair value	$ 368,346	$ 144,371
Derivative, Collateral, Obligation to Return Securities	174	802
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	368,172	143,569
Derivative liability, gross liability	180,834	76,067
Derivative liability, Collateral, Right to Reclaim Securities	(174)	(802)
Derivative liability, Collateral, Right to Reclaim Cash	(180,576)	(75,265)
Derivative liability, Net Amount	84	0
Interest Rate Swap [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	368,178	144,179
Derivative, Collateral, Obligation to Return Securities	6	757
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	368,172	143,422
Derivative liability, gross liability	180,582	76,022
Derivative liability, Collateral, Right to Reclaim Securities	(6)	(757)
Derivative liability, Collateral, Right to Reclaim Cash	(180,576)	(75,265)
Derivative liability, Net Amount	0	0
Foreign Exchange Contract [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	168	192
Derivative, Collateral, Obligation to Return Securities	168	45
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	0	147
Derivative liability, gross liability	252	45
Derivative liability, Collateral, Right to Reclaim Securities	(168)	(45)
Derivative liability, Collateral, Right to Reclaim Cash	0	0
Derivative liability, Net Amount	$ 84	$ 0