Derivatives Volume of Activity (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Not Designated as Hedging Instrument, Economic Hedge | Interest rate swaptions
Derivative [Line Items]
Derivative, Notional Amount	$ (500,000)	$ (500,000)
Additions	0
Not Designated as Hedging Instrument, Economic Hedge | U.S. Treasury futures | Short position
Derivative [Line Items]
Derivative, Notional Amount	(4,350,000)	(3,890,000)
Additions	(9,130,000)
Settlements, Terminations, or Pair-Offs	(8,670,000)
Not Designated as Hedging Instrument, Trading | TBA securities | Long position
Derivative [Line Items]
Derivative, Notional Amount	(3,323,000)	$ (1,530,000)
Additions	(14,957,000)
Settlements, Terminations, or Pair-Offs	$ (13,164,000)