Equity - Narrative (Details) $ / shares in Units, $ in Millions			3 Months Ended	12 Months Ended
	Sep. 08, 2008 USD ($) $ / shares shares	Sep. 08, 2008 USD ($) $ / shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Mar. 31, 2023 USD ($)	Dec. 31, 2021 USD ($) shares	Sep. 07, 2008 $ / shares
Class of Stock [Line Items]
Common stock, shares outstanding | shares			1,158,087,567	1,158,087,567		1,158,087,567
Increase in net worth			$ 1,400
Proceeds from issuance of common stock				$ 70,000
Preferred stock, covenant, maximum mortgage assets			225,000	225,000
Mortgage assets			79,500	79,500
FHFA debt limit			$ 270,000	$ 270,000
Convertible Series 2004-1
Class of Stock [Line Items]
Conversion price per share (in dollars per share) | $ / shares			$ 94.31	$ 94.31
Conversion rate			1,060.3329	1,060.3329
Preferred stock, redemption price (in dollars per share) | $ / shares			$ 105,000	$ 105,000
Series 2008-2
Class of Stock [Line Items]
Shares of variable liquidation preference senior preferred stock issued | shares	1,000,000
Aggregate liquidation preference of senior preferred stock	$ 1,000	$ 1,000
Value assigned to Treasury's commitment and recorded as a reduction to additional paid-in-capital		$ 4,500
Senior preferred stock, stated value per share (in dollars per share) | $ / shares	$ 1,000	$ 1,000	$ 120,836	$ 120,836
Preferred stock covenant maximum fair market value of assets and properties per transaction			$ 250	$ 250
Preferred stock, covenant, maximum mortgage assets, ratio						120.00%
Minimum | Series O
Class of Stock [Line Items]
Preferred stock, redemption price (in dollars per share) | $ / shares			$ 50	$ 50
Maximum | Series O
Class of Stock [Line Items]
Preferred stock, redemption price (in dollars per share) | $ / shares			$ 52.50	$ 52.50
US Treasury
Class of Stock [Line Items]
Percentage of common shares attributable to warrants							79.90%
Aggregate liquidation preference of senior preferred stock			$ 180,300	$ 180,300
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement			119,800	119,800
Common stock warrant exercise price (in dollars per share) | $ / shares							$ 0.00001
Total remaining funding available from US Treasury pursuant to the senior preferred stock agreement			113,900	113,900
Fannie Mae
Class of Stock [Line Items]
Preferred stock, covenant, maximum mortgage assets			202,500	202,500
Face amount			$ 139,300	$ 139,300		$ 202,500
Forecast | US Treasury
Class of Stock [Line Items]
Aggregate liquidation preference of senior preferred stock					$ 181,800