Loans, Lending Commitments and Related Allowance for Credit Losses - Allowance for Credit Losses Rollforward - Loans and Lending Commitments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Allowance for loan losses rollforward
Beginning balance			$ 1,169	$ 839
Gross charge-offs			(54)	(101)
Recoveries			4
Net (charge-offs) recoveries			(50)
Provision (release)	$ 85	$ 138	63	339
Other			(7)	4
Ending balance	$ 1,175	$ 1,081	$ 1,175	$ 1,081
Percent of loans to total loans	100.00%	100.00%	100.00%	100.00%
Allowance for lending commitments rollforward
Beginning balance			$ 551	$ 504
Provision (release)	$ (9)	$ 23	7	56
Other			(3)	2
Ending balance	555	562	555	562
Total ending balance	1,730	1,643	1,730	1,643
Corporate
Allowance for loan losses rollforward
Beginning balance			241	235
Gross charge-offs			0	(30)
Recoveries			0
Net (charge-offs) recoveries			0
Provision (release)			1	50
Other			(1)	2
Ending balance	$ 241	$ 257	$ 241	$ 257
Percent of loans to total loans	3.00%	4.00%	3.00%	4.00%
Allowance for lending commitments rollforward
Beginning balance			$ 431	$ 411
Provision (release)			8	35
Other			(5)	2
Ending balance	$ 434	$ 448	434	448
Total ending balance	675	705	675	705
Secured lending facilities
Allowance for loan losses rollforward
Beginning balance			153	153
Gross charge-offs			(11)	0
Recoveries			0
Net (charge-offs) recoveries			(11)
Provision (release)			2	3
Other			(1)	0
Ending balance	$ 143	$ 156	$ 143	$ 156
Percent of loans to total loans	21.00%	19.00%	21.00%	19.00%
Allowance for lending commitments rollforward
Beginning balance			$ 70	$ 51
Provision (release)			0	10
Other			(1)	0
Ending balance	$ 69	$ 61	69	61
Total ending balance	212	217	212	217
Commercial real estate
Allowance for loan losses rollforward
Beginning balance			463	275
Gross charge-offs			(41)	(69)
Recoveries			4
Net (charge-offs) recoveries			(37)
Provision (release)			46	178
Other			(3)	1
Ending balance	$ 469	$ 385	$ 469	$ 385
Percent of loans to total loans	4.00%	4.00%	4.00%	4.00%
Allowance for lending commitments rollforward
Beginning balance			$ 26	$ 15
Provision (release)			3	7
Other			0	0
Ending balance	$ 29	$ 22	29	22
Total ending balance	498	407	498	407
Residential real estate
Allowance for loan losses rollforward
Beginning balance			100	87
Gross charge-offs			0	0
Recoveries			0
Net (charge-offs) recoveries			0
Provision (release)			(6)	25
Other			0	0
Ending balance	$ 94	$ 112	$ 94	$ 112
Percent of loans to total loans	30.00%	28.00%	30.00%	28.00%
Allowance for lending commitments rollforward
Beginning balance			$ 4	$ 4
Provision (release)			0	1
Other			0	0
Ending balance	$ 4	$ 5	4	5
Total ending balance	98	117	98	117
SBL and Other
Allowance for loan losses rollforward
Beginning balance			212	89
Gross charge-offs			(2)	(2)
Recoveries			0
Net (charge-offs) recoveries			(2)
Provision (release)			20	83
Other			(2)	1
Ending balance	$ 228	$ 171	$ 228	$ 171
Percent of loans to total loans	42.00%	45.00%	42.00%	45.00%
Allowance for lending commitments rollforward
Beginning balance			$ 20	$ 23
Provision (release)			(4)	3
Other			3	0
Ending balance	$ 19	$ 26	19	26
Total ending balance	$ 247	$ 197	$ 247	$ 197