Offsetting Arrangements - Repo, Sec Lending Transactions Maturity by Category (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	$ 223,832	$ 197,757
Securities lending transactions	21,661	16,605
Gross amount of recognized liabilities for repurchase agreements and securities lending	245,493	214,362
U.S. Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	223,832	197,757
Securities lending transactions	118	6
Corporate debt securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	171	281
Equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	14,629	9,452
Other
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	6,743	6,866
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	221,904	196,212
Securities lending transactions	17,836	14,278
Gross amount of recognized liabilities for repurchase agreements and securities lending	239,740	210,490
Overnight and Continuous | U.S. Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	221,904	196,212
Securities lending transactions	118	6
Overnight and Continuous | Corporate debt securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	158	278
Overnight and Continuous | Equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	10,817	7,128
Overnight and Continuous | Other
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	6,743	6,866
Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	0	0
Securities lending transactions	15	20
Gross amount of recognized liabilities for repurchase agreements and securities lending	15	20
Up to 30 Days | U.S. Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	0	0
Securities lending transactions	0	0
Up to 30 Days | Corporate debt securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	0	0
Up to 30 Days | Equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	15	20
Up to 30 Days | Other
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	0	0
30-90 days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	600	185
Securities lending transactions	54	16
Gross amount of recognized liabilities for repurchase agreements and securities lending	654	201
30-90 days | U.S. Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	600	185
Securities lending transactions	0	0
30-90 days | Corporate debt securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	13	3
30-90 days | Equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	41	13
30-90 days | Other
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	0	0
Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	1,328	1,360
Securities lending transactions	3,756	2,291
Gross amount of recognized liabilities for repurchase agreements and securities lending	5,084	3,651
Greater than 90 Days | U.S. Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements	1,328	1,360
Securities lending transactions	0	0
Greater than 90 Days | Corporate debt securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	0	0
Greater than 90 Days | Equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	3,756	2,291
Greater than 90 Days | Other
Assets Sold under Agreements to Repurchase [Line Items]
Securities lending transactions	$ 0	$ 0