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
Mar. 31, 2022	Mar. 31, 2021
Allowance for loan losses rollforward
Beginning balance	$ 654	$ 835
Gross charge-offs	(11)	(10)
Provision (release)	39	(58)
Other	(3)	(5)
Ending balance	$ 679	$ 762
Percent of loans to total loans	100.00%	100.00%
Allowance for lending commitments rollforward
Beginning balance	$ 444	$ 396
Provision (release)	18	(40)
Other	(3)	(2)
Ending balance	459	354
Corporate
Allowance for loan losses rollforward
Beginning balance	165	309
Gross charge-offs	0	(1)
Provision (release)	6	(56)
Other	(1)	(2)
Ending balance	$ 170	$ 250
Percent of loans to total loans	3.00%	4.00%
Allowance for lending commitments rollforward
Beginning balance	$ 356	$ 323
Provision (release)	20	(33)
Other	(3)	(1)
Ending balance	373	289
Secured lending facilities
Allowance for loan losses rollforward
Beginning balance	163	198
Gross charge-offs	(3)	0
Provision (release)	12	(3)
Other	0	(2)
Ending balance	$ 172	$ 193
Percent of loans to total loans	16.00%	18.00%
Allowance for lending commitments rollforward
Beginning balance	$ 41	$ 38
Provision (release)	8	(4)
Other	0	1
Ending balance	49	35
Commercial real estate
Allowance for loan losses rollforward
Beginning balance	206	211
Gross charge-offs	(7)	(9)
Provision (release)	6	5
Other	(2)	(1)
Ending balance	$ 203	$ 206
Percent of loans to total loans	5.00%	5.00%
Allowance for lending commitments rollforward
Beginning balance	$ 20	$ 11
Provision (release)	(7)	(2)
Other	0	(1)
Ending balance	13	8
Residential real estate
Allowance for loan losses rollforward
Beginning balance	60	59
Gross charge-offs	0	0
Provision (release)	13	(5)
Other	0	0
Ending balance	$ 73	$ 54
Percent of loans to total loans	26.00%	25.00%
Allowance for lending commitments rollforward
Beginning balance	$ 1	$ 1
Provision (release)	0	0
Other	0	0
Ending balance	1	1
SBL and Other
Allowance for loan losses rollforward
Beginning balance	60	58
Gross charge-offs	(1)	0
Provision (release)	2	1
Other	0	0
Ending balance	$ 61	$ 59
Percent of loans to total loans	50.00%	48.00%
Allowance for lending commitments rollforward
Beginning balance	$ 26	$ 23
Provision (release)	(3)	(1)
Other	0	(1)
Ending balance	$ 23	$ 21

Amount of other addition (reduction) in allowance reserve for credit loss.

No definition available.

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Period Type:	duration

- Definition

Financing Receivable, Loans Held for Investment by Loan Type to Total Loans Held for Investment

+ References

No definition available.

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- Definition

A valuation allowance for credit exposures related to off-balance-sheet loan commitments.

+ References

No definition available.

+ Details

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- Definition

Other increase (decrease) in the allowance for credit exposures on off-balance-sheet loan commitments.

+ References

No definition available.

+ Details

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- References

No definition available.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

+ Details

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- Definition

Amount of writeoff of financing receivable, charged against allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
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-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 79
-URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448

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Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

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Balance Type:	debit
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- Definition

Amount of credit loss expense (reversal of expense) for financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(11))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

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