Derivatives - Offsetting Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Offsetting Assets [Line Items]
Gross Amounts	$ 772,451	$ 199,073
Gross Amounts Not Offset, Financial Instruments	(3,772)	(10,900)
Gross Amounts Not Offset, Cash Collateral	(682,198)	(157,493)
Total Net	86,481	30,680
Interest rate swap contracts
Offsetting Assets [Line Items]
Gross Amounts	765,923	187,661
Gross Amounts Not Offset, Financial Instruments	0	(7,185)
Gross Amounts Not Offset, Cash Collateral	(698,422)	(161,529)
Total Net	67,501	18,947
Futures contracts
Offsetting Assets [Line Items]
Gross Amounts	2,160
Gross Amounts Not Offset, Financial Instruments	0
Gross Amounts Not Offset, Cash Collateral	9,065
Total Net	11,225
TBA Agency Securities
Offsetting Assets [Line Items]
Gross Amounts	4,368	11,412
Gross Amounts Not Offset, Financial Instruments	(3,772)	(3,715)
Gross Amounts Not Offset, Cash Collateral	7,159	4,036
Total Net	$ 7,755	$ 11,733