Loans and Allowance for Credit Losses - Activity in the Allowance for Credit Losses for Loans Held for Investment (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			$ 135,000,000
Charge-offs	$ (7,000,000)
Provision for credit losses	10,000,000	$ (18,000,000)	37,000,000	$ 26,000,000
Ending balance	136,000,000		136,000,000
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		2,000,000	0	2,000,000
Charge-offs	0	0		0
Provision		(2,000,000)		(2,000,000)
Ending balance	0	0	0	0
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,000,000		1,000,000
Charge-offs	0		0
Provision	0		0
Ending balance	1,000,000		1,000,000
Leveraged Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	71,000,000	82,000,000	72,000,000	73,000,000
Charge-offs	(11,000,000)	(8,000,000)	(17,000,000)	(11,000,000)
Provision for credit losses	(4,000,000)	6,000,000	1,000,000	18,000,000
Ending balance	56,000,000	80,000,000	56,000,000	80,000,000
Other Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,000,000	4,000,000	3,000,000	5,000,000
Charge-offs	0	0	0	0
Provision for credit losses	0	(1,000,000)	1,000,000	(2,000,000)
Ending balance	4,000,000	3,000,000	4,000,000	3,000,000
Other Loans | Fund Finance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	3,000,000	2,000,000	3,000,000	2,000,000
Other Loans | Other Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	1,000,000	1,000,000	1,000,000	1,000,000
Commercial Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	60,000,000	29,000,000	60,000,000	19,000,000
Charge-offs	0	0	(25,000,000)	0
Provision for credit losses	16,000,000	8,000,000	41,000,000	18,000,000
Ending balance	76,000,000	37,000,000	76,000,000	37,000,000
Off-Balance Sheet Commitments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10,000,000	16,000,000	14,000,000	23,000,000
Charge-offs	0	0	0	0
Provision for credit losses	(2,000,000)	(1,000,000)	(6,000,000)	(8,000,000)
Ending balance	8,000,000	15,000,000	8,000,000	15,000,000
All Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		29,000,000		(1,000,000)
Charge-offs		0		0
Provision for credit losses		(28,000,000)		2,000,000
Ending balance		1,000,000		1,000,000
Total
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	146,000,000	162,000,000	150,000,000	121,000,000
Charge-offs	(11,000,000)	(8,000,000)	(42,000,000)	(11,000,000)
Provision for credit losses	10,000,000	(18,000,000)	37,000,000	26,000,000
Ending balance	$ 145,000,000	$ 136,000,000	$ 145,000,000	$ 136,000,000