Fair Value Measurement - Nonrecurring Basis (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities adjusted based on the measurement alternative	$ 3,564	$ 4,673	$ 3,564	$ 4,673	$ 4,500
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	2,145	1,936	2,145	1,936
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Total nonrecurring fair value gains/(losses)	(283)	(132)	(364)	(227)
Nonrecurring | Accounts payable and other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Total nonrecurring fair value gains/(losses)	0	0	0	0
Nonrecurring | Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	1,638	1,643	1,638	1,643
Total nonrecurring fair value gains/(losses)	(105)	(96)	(149)	(128)
Nonrecurring | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	507	293	507	293
Total nonrecurring fair value gains/(losses)	(178)	(36)	(215)	(99)
Nonrecurring | Other assets using measurement alternative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nonrecurring fair value gains/(losses)	(109)	(32)	(147)	(93)
Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	0	0	0	0
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 1 | Accounts payable and other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 1 | Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 1 | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	866	810	866	810
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 2 | Accounts payable and other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 2 | Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	860	803	860	803
Nonrecurring | Level 2 | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	6	7	6	7
Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	1,279	1,126	1,279	1,126
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 3 | Accounts payable and other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value on a nonrecurring basis	0	0	0	0
Nonrecurring | Level 3 | Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	778	840	778	840
Nonrecurring | Level 3 | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value on a nonrecurring basis	501	$ 286	501	$ 286
Equity securities adjusted based on the measurement alternative	$ 336		$ 336