Loans, Lending Commitments and Related Allowance for Credit Losses - Allowance for Credit Losses Rollforward - Loans and Lending Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for loan losses rollforward
Beginning balance	$ 835	$ 349	$ 238
Effect of CECL adoption		9
Gross charge-offs	(126)	(105)	(2)
Recoveries		8
Net (charge-offs) recoveries		(97)
Provision (release)	(48)	558	119
Other	(7)	16	(6)
Ending balance	654	835	349
Allowance for lending commitments rollforward
Beginning balance	396	241	203
Effect of CECL adoption		(50)
Provision (release)	52	203	42
Other	(4)	2	(4)
Ending balance	$ 444	$ 396	$ 241
Loans to total loans	100.00%	100.00%	100.00%
Corporate
Allowance for loan losses rollforward
Beginning balance	$ 309	$ 115	$ 62
Effect of CECL adoption		(2)
Gross charge-offs	(23)	(39)	0
Recoveries		4
Net (charge-offs) recoveries		(35)
Provision (release)	(119)	224	58
Other	(2)	7	(5)
Ending balance	165	309	115
Allowance for lending commitments rollforward
Beginning balance	323	201	177
Effect of CECL adoption		(41)
Provision (release)	37	161	27
Other	(4)	2	(3)
Ending balance	$ 356	$ 323	$ 201
Loans to total loans	3.00%	4.00%	4.00%
Secured lending facilities
Allowance for loan losses rollforward
Beginning balance	$ 198	$ 101	$ 60
Effect of CECL adoption		(42)
Gross charge-offs	(67)	0	0
Recoveries		0
Net (charge-offs) recoveries		0
Provision (release)	34	136	42
Other	(2)	3	(1)
Ending balance	163	198	101
Allowance for lending commitments rollforward
Beginning balance	38	27	16
Effect of CECL adoption		(11)
Provision (release)	2	22	11
Other	1	0	0
Ending balance	$ 41	$ 38	$ 27
Loans to total loans	18.00%	19.00%	21.00%
Commercial real estate
Allowance for loan losses rollforward
Beginning balance	$ 211	$ 75	$ 67
Effect of CECL adoption		34
Gross charge-offs	(27)	(64)	0
Recoveries		0
Net (charge-offs) recoveries		(64)
Provision (release)	25	197	8
Other	(3)	(31)	0
Ending balance	206	211	75
Allowance for lending commitments rollforward
Beginning balance	11	7	3
Effect of CECL adoption		1
Provision (release)	10	7	4
Other	(1)	(4)	0
Ending balance	$ 20	$ 11	$ 7
Loans to total loans	4.00%	5.00%	7.00%
Residential real estate
Allowance for loan losses rollforward
Beginning balance	$ 59	$ 25	$ 20
Effect of CECL adoption		21
Gross charge-offs	(1)	(1)	(2)
Recoveries		0
Net (charge-offs) recoveries		(1)
Provision (release)	1	14	7
Other	1	0	0
Ending balance	60	59	25
Allowance for lending commitments rollforward
Beginning balance	1	0	0
Effect of CECL adoption		2
Provision (release)	0	(1)	0
Other	0	0	0
Ending balance	$ 1	$ 1	$ 0
Loans to total loans	25.00%	26.00%	25.00%
SBL and Other
Allowance for loan losses rollforward
Beginning balance	$ 58	$ 33	$ 29
Effect of CECL adoption		(2)
Gross charge-offs	(8)	(1)	0
Recoveries		4
Net (charge-offs) recoveries		3
Provision (release)	11	(13)	4
Other	(1)	37	0
Ending balance	60	58	33
Allowance for lending commitments rollforward
Beginning balance	23	6	7
Effect of CECL adoption		(1)
Provision (release)	3	14	0
Other	0	4	(1)
Ending balance	$ 26	$ 23	$ 6
Loans to total loans	50.00%	46.00%	43.00%