Derivatives Volume of Activity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Not Designated as Hedging Instrument, Economic Hedge | Interest rate swaptions
Derivatives [Roll Forward]
Derivative, Notional Amount	$ 500,000
Derivative, Notional Amount, Derivative Instruments Added	0
Derivative, Notional Amount, Derivative Instruments Maturing, Settled, Terminated, or Paired-Off	(500,000)
Derivative, Notional Amount	0
Not Designated as Hedging Instrument, Economic Hedge | U.S. Treasury futures | Short position
Derivatives [Roll Forward]
Derivative, Notional Amount	3,890,000
Derivative, Notional Amount, Derivative Instruments Added	(13,480,000)
Derivative, Notional Amount, Derivative Instruments Maturing, Settled, Terminated, or Paired-Off	14,750,000
Derivative, Notional Amount	5,160,000
Not Designated as Hedging Instrument, Economic Hedge | Options on U.S. Treasury futures
Derivatives [Roll Forward]
Derivative, Notional Amount	0
Derivative, Notional Amount, Derivative Instruments Added	750,000
Derivative, Notional Amount	750,000
Not Designated as Hedging Instrument, Trading | TBA securities | Long position
Derivatives [Roll Forward]
Derivative, Notional Amount	1,530,000
Derivative, Notional Amount, Derivative Instruments Added	27,093,000
Derivative, Notional Amount, Derivative Instruments Maturing, Settled, Terminated, or Paired-Off	(25,104,000)
Derivative, Notional Amount	$ 3,519,000