Derivative Financial Instruments Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Offsetting Assets [Line Items]
Derivative asset, fair value	$ 331,269	$ 144,371
Financial Instruments	(7)	(802)
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	331,262	143,569
Derivative liability, gross liability	165,210	76,067
Derivative liability, Collateral, Right to Reclaim Securities	(7)	(802)
Derivative liability, Collateral, Right to Reclaim Cash	(165,203)	(75,265)
Derivative liability, Net Amount	0	0
Interest Rate Swap
Offsetting Assets [Line Items]
Derivative asset, fair value	330,951	144,179
Financial Instruments	(2)	(757)
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	330,949	143,422
Derivative liability, gross liability	165,205	76,022
Derivative liability, Collateral, Right to Reclaim Securities	(2)	(757)
Derivative liability, Collateral, Right to Reclaim Cash	(165,203)	(75,265)
Derivative liability, Net Amount	0	0
Foreign Exchange Contract
Offsetting Assets [Line Items]
Derivative asset, fair value	318	192
Financial Instruments	(5)	(45)
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	313	147
Derivative liability, gross liability	5	45
Derivative liability, Collateral, Right to Reclaim Securities	(5)	(45)
Derivative liability, Collateral, Right to Reclaim Cash	0	0
Derivative liability, Net Amount	$ 0	$ 0