Netting Arrangements (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Assets:
Derivative assets, gross amount	$ 408,000,000	$ 1,951,000,000
Derivative asset, gross amount offset	(237,000,000)	(905,000,000)
Derivative assets, net amount presented in our consolidated balance sheets	171,000,000	1,046,000,000
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	(133,000,000)	(406,000,000)
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	0	(53,000,000)
Derivative assets, net amount	38,000,000	587,000,000
Securities purchased under agreements to resell, or similar arrangements, gross amount	64,843,000,000	46,644,000,000
Securities purchased under agreements to resell or similar arrangements, gross amount offset	0	0
Securities purchased under agreements to resell or similar arrangements, net amount presented in our consolidated balance sheets	64,843,000,000	46,644,000,000
Securities purchased under agreements to resell, under master netting arrangement, amounts not offset in our consolidated balance sheets, financial instruments	0	0
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	(64,843,000,000)	(46,644,000,000)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0
Total assets, gross amount	65,251,000,000	48,595,000,000
Total assets, gross amount offset	(237,000,000)	(905,000,000)
Total assets, net amount presented in the consolidated balance sheets	65,014,000,000	47,690,000,000
Total assets, under the master netting arrangements, not offset in our consolidated balance sheets, financial instruments	(133,000,000)	(406,000,000)
Total assets, under master netting arrangements, not offset in our consolidated balance sheets, collateral	(64,843,000,000)	(46,697,000,000)
Total assets, net amount	38,000,000	587,000,000
Liabilities:
Derivative liabilities, gross amount offset	1,173,000,000	995,000,000
Total liabilities, gross amount	(1,385,000,000)	(2,441,000,000)
Total liabilities, gross amount offset	1,173,000,000	995,000,000
Total liabilities, net amount presented in our consolidated balance sheets	(212,000,000)	(1,446,000,000)
Total liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial statements	133,000,000	406,000,000
Total liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	66,000,000	1,019,000,000
Total liabilities, net amount	(13,000,000)	(21,000,000)
Amount eligible to be repledged by counterparty	2,500,000,000	4,700,000,000
Securities received as collateral	64,900,000,000	46,600,000,000
Fair value of securities received as collateral that can be resold or repledged	25,600,000,000	46,600,000,000
Fair value of securities received as collateral that have been resold or repledged	0	0
Derivative asset, not subject to master netting arrangement	0	179,000,000
Derivative liability, not subject to master netting arrangement	21,000,000	49,000,000
Securities purchased under agreements to resell or similar arrangements	20,743,000,000	28,200,000,000
Mortgage commitment derivatives
Assets:
Derivative assets, gross amount	169,000,000	989,000,000
Derivative asset, gross amount offset	0	0
Derivative assets, net amount presented in our consolidated balance sheets	169,000,000	989,000,000
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	(133,000,000)	(406,000,000)
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	0	(53,000,000)
Derivative assets, net amount	36,000,000	530,000,000
Liabilities:
Derivative liabilities, gross amount	(197,000,000)	(1,426,000,000)
Derivative liabilities, gross amount offset	0	0
Derivative liabilities, net amount presented in our consolidated balance sheets	(197,000,000)	(1,426,000,000)
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	133,000,000	406,000,000
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	56,000,000	1,017,000,000
Derivative liabilities, net amount	(8,000,000)	(3,000,000)
OTC risk management derivatives | Risk management derivatives
Assets:
Derivative assets, gross amount	239,000,000	962,000,000
Derivative asset, gross amount offset	(237,000,000)	(952,000,000)
Derivative assets, net amount presented in our consolidated balance sheets	2,000,000	10,000,000
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	0	0
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	0	0
Derivative assets, net amount	2,000,000	10,000,000
Liabilities:
Derivative liabilities, gross amount	(1,188,000,000)	(1,015,000,000)
Derivative liabilities, gross amount offset	1,183,000,000	999,000,000
Derivative liabilities, net amount presented in our consolidated balance sheets	(5,000,000)	(16,000,000)
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	0	0
Derivative liabilities, net amount	(5,000,000)	(16,000,000)
Cleared risk management derivatives | Risk management derivatives
Assets:
Derivative assets, gross amount	0	0
Derivative asset, gross amount offset	0	47,000,000
Derivative assets, net amount presented in our consolidated balance sheets	0	47,000,000
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	0	0
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	0	0
Derivative assets, net amount	0	47,000,000
Liabilities:
Derivative liabilities, gross amount	0	0
Derivative liabilities, gross amount offset	(10,000,000)	(4,000,000)
Derivative liabilities, net amount presented in our consolidated balance sheets	(10,000,000)	(4,000,000)
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	10,000,000	2,000,000
Derivative liabilities, net amount	0	(2,000,000)
Cash and Cash Equivalents
Liabilities:
Securities purchased under agreements to resell or similar arrangements	29,100,000,000	18,400,000,000
Restricted Cash and Cash Equivalents
Liabilities:
Securities purchased under agreements to resell or similar arrangements	$ 15,000,000,000	$ 0