Derivatives and Hedging Instruments - Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Derivative assets
Gross Amounts	$ 38,447	$ 76,640
Gross Amounts Offset in the Balance Sheet	0	0
Net Amounts	38,447	76,640
Gross Amounts not Offset in the Balance Sheet	(35,100)	(37,820)
Net	3,347	38,820
Derivative liabilities
Gross Amounts	415,628	45,832
Gross Amounts Offset in the Balance Sheet	0	0
Net Amounts	415,628	45,832
Gross Amounts not Offset in the Balance Sheet	(35,100)	(37,820)
Net	$ 380,528	$ 8,012