Derivatives Volume of Activity (Details) $ in Thousands	12 Months Ended
	Dec. 31, 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	19,945,000
Derivative, Notional Amount, Derivative Instruments Maturing, Settled, Terminated, or Paired-Off	(18,915,000)
Derivative, Notional Amount	4,920,000
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	1,250,000
Derivative, Notional Amount, Derivative Instruments Maturing, Settled, Terminated, or Paired-Off	(1,000,000)
Derivative, Notional Amount	250,000
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	35,955,000
Derivative, Notional Amount, Derivative Instruments Maturing, Settled, Terminated, or Paired-Off	(34,616,000)
Derivative, Notional Amount	$ 2,869,000