Loans and Allowance for Credit Losses - Activity in the Allowance for Credit Losses for Loans Held for Investment (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			$ 122
Provision	$ (15)	$ 52
Ending balance	100		100
Leveraged Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	92	83	97	$ 61
Charge-offs	(1)	(14)	(1)	(19)
Provision	(19)	43	(20)	70
Currency translation	2	1	(2)	1
Ending balance	74	113	74	113
Other Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	12	10	17	10
Charge-offs	0	0	0	0
Provision	0	10	(5)	10
Currency translation	0	0	0	0
Ending balance	12	20	12	20
Other Loans \| Fund Finance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	10		10
Other Loans \| Other Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	2		2
Commercial Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14	4	8	2
Charge-offs	0	0	0	0
Provision	0	4	6	6
Currency translation	0	0	0	0
Ending balance	14	8	14	8
Held-to-Maturity Securities
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	2		3
Charge-offs	0		0
Provision	0		(1)
Currency translation	0		0
Ending balance	2		2
Off Balance Sheet Commitments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	15	22	22	19
Charge-offs	0	0	0	0
Provision	4	(4)	(3)	(1)
Currency translation	0	0	0	0
Ending balance	19	18	19	18
All Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	5	1	1
Charge-offs	0	0	0	0
Provision	0	(1)	(1)	3
Currency translation	0	0	0	0
Ending balance	0	4	0	4
Total Credit Reserve
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	135	124	148	93
Charge-offs	(1)	(14)	(1)	(19)
Provision	(15)	52	(24)	88
Currency translation	(2)	1	(2)	1
Ending balance	$ 121	$ 163	$ 121	$ 163

Amount of foreign currency translation gain (loss) which (increases) decreases allowance for credit loss on financing receivable.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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

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

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