Netting Arrangements (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Assets:
Derivative assets, gross amount	$ 513,000,000	$ 440,000,000
Derivative asset, gross amount offset	(362,000,000)	(283,000,000)
Derivative assets, net amount presented in our consolidated balance sheets	151,000,000	157,000,000
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	(91,000,000)	(23,000,000)
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	(14,000,000)	(9,000,000)
Derivative assets, net amount	46,000,000	125,000,000
Securities purchased under agreements to resell, or similar arrangements, gross amount	56,250,000,000	65,425,000,000
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	56,250,000,000	65,425,000,000
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	(56,250,000,000)	(65,425,000,000)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0
Total assets, gross amount	56,763,000,000	65,865,000,000
Total assets, gross amount offset	(362,000,000)	(283,000,000)
Total assets, net amount presented in the consolidated balance sheets	56,401,000,000	65,582,000,000
Total assets, under the master netting arrangements, not offset in our consolidated balance sheets, financial instruments	(91,000,000)	(23,000,000)
Total assets, under master netting arrangements, not offset in our consolidated balance sheets, collateral	(56,264,000,000)	(65,434,000,000)
Total assets, net amount	46,000,000	125,000,000
Liabilities:
Total liabilities, gross amount	(2,505,000,000)	(3,327,000,000)
Total liabilities, gross amount offset	2,367,000,000	3,200,000,000
Total liabilities, net amount presented in our consolidated balance sheets	(138,000,000)	(127,000,000)
Total liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial statements	91,000,000	23,000,000
Total liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	10,000,000	80,000,000
Total liabilities, net amount	(37,000,000)	(24,000,000)
Securities received as collateral	56,300,000,000	65,500,000,000
Fair value of securities received as collateral that can be resold or repledged	49,000,000,000.0	55,400,000,000
Fair value of securities received as collateral that have been resold or repledged	0	0
Derivative asset, not subject to master netting arrangement	28,000,000	45,000,000
Derivative liability, not subject to master netting arrangement	(16,000,000)	(13,000,000)
Securities purchased under agreements to resell	15,975,000,000	30,700,000,000
Asset Pledged as Collateral with Right
Assets:
Total assets, under master netting arrangements, not offset in our consolidated balance sheets, collateral	(2,700,000,000)	(2,200,000,000)
Mortgage commitment derivatives
Assets:
Derivative assets, gross amount	112,000,000	112,000,000
Derivative asset, gross amount offset	0	0
Derivative assets, net amount presented in our consolidated balance sheets	112,000,000	112,000,000
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	(91,000,000)	(23,000,000)
Derivative assets, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	(14,000,000)	(9,000,000)
Derivative assets, net amount	7,000,000	80,000,000
Liabilities:
Derivative liabilities, gross amount	(137,000,000)	(104,000,000)
Derivative liabilities, gross amount offset	0	0
Derivative liabilities, net amount presented in our consolidated balance sheets	(137,000,000)	(104,000,000)
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, financial instruments	91,000,000	23,000,000
Derivative liabilities, under master netting arrangements, amounts not offset in our consolidated balance sheets, collateral	9,000,000	77,000,000
Derivative liabilities, net amount	(37,000,000)	(4,000,000)
OTC risk management derivatives | Risk management derivatives
Assets:
Derivative assets, gross amount	401,000,000	328,000,000
Derivative asset, gross amount offset	(383,000,000)	(294,000,000)
Derivative assets, net amount presented in our consolidated balance sheets	18,000,000	34,000,000
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	18,000,000	34,000,000
Liabilities:
Derivative liabilities, gross amount	(2,368,000,000)	(3,223,000,000)
Derivative liabilities, gross amount offset	2,368,000,000	3,203,000,000
Derivative liabilities, net amount presented in our consolidated balance sheets	0	(20,000,000)
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	0	(20,000,000)
Cleared risk management derivatives | Risk management derivatives
Assets:
Derivative assets, gross amount	0	0
Derivative asset, gross amount offset	21,000,000	11,000,000
Derivative assets, net amount presented in our consolidated balance sheets	21,000,000	11,000,000
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	21,000,000	11,000,000
Liabilities:
Derivative liabilities, gross amount	0	0
Derivative liabilities, gross amount offset	(1,000,000)	(3,000,000)
Derivative liabilities, net amount presented in our consolidated balance sheets	(1,000,000)	(3,000,000)
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	1,000,000	3,000,000
Derivative liabilities, net amount	0	0
Cash and Cash Equivalents
Liabilities:
Securities purchased under agreements to resell	25,400,000,000	21,800,000,000
Restricted Cash and Cash Equivalent
Liabilities:
Securities purchased under agreements to resell	$ 14,900,000,000	$ 12,900,000,000