Fair Value Measurement - Nonrecurring Basis (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 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	$ 4,467	$ 3,910	$ 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	1,561	1,743
Total liabilities measured at fair value on a nonrecurring basis	0	3
Total nonrecurring fair value gains/(losses)	(101)	(105)
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	3
Total nonrecurring fair value gains/(losses)	0	(3)
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	1,339	1,542
Total nonrecurring fair value gains/(losses)	(60)	(37)
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	222	201
Total nonrecurring fair value gains/(losses)	(41)	(65)
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)	(39)	(61)
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
Total liabilities measured at fair value on a nonrecurring basis	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
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
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
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	880	731
Total liabilities measured at fair value on a nonrecurring basis	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
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	871	709
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	9	22
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	681	1,012
Total liabilities measured at fair value on a nonrecurring basis	0	3
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	3
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	468	833
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	213	$ 179
Equity securities adjusted based on the measurement alternative	$ 191