Regulatory Capital Requirements (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Component of critical capital requirement, percentage of the unpaid principal balance of outstanding Fannie Mae MBS held by third parties	0.45%
Component of statutory minimum capital requirement, percentage of the unpaid principal balance of outstanding Fannie Mae MBS held by third parties	0.45%
Core capital	$ (73,517)	$ (95,694)
Statutory minimum capital requirement	26,810	28,603
Deficit of core capital relative to statutory minimum capital requirement	$ (100,327)	$ (124,297)
Component of statutory minimum capital requirement, percentage of on-balance sheet assets, except those underlying Fannie Mae MBS held by third parties	2.50%
Component of statutory minimum capital requirement, maximum percentage of other off-balance sheet obligations	0.45%
Component of critical capital requirement, percentage of on-balance sheet assets, except those underlying Fannie Mae MBS held by third parties	1.25%
Component of critical capital requirement, percentage of other off-balance sheet obligations	0.25%