Other Assets and Liabilities - Summary of Unfunded Loan Commitment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 133,024	$ 122,221	$ 124,679	$ 130,388	$ 128,945	$ 172,100	$ 173,549
Increase (decrease) in CECL reserve	11,407	10,803	(2,458)		1,443	(43,155)	(1,449)
Ending balance	144,431	133,024	122,221	124,679	130,388	128,945	172,100
US Loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	33,311	26,241	26,885	20,926	17,673	44,534	42,995
Increase (decrease) in CECL reserve	8,280	7,070	(644)		3,253	(26,861)	1,539
Ending balance	41,591	33,311	26,241	26,885	20,926	17,673	44,534
Non-U.S. Loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	11,344	10,209	10,263	8,546	8,829	24,600	27,734
Increase (decrease) in CECL reserve	45	1,135	(54)		(283)	(15,771)	(3,134)
Ending balance	11,389	11,344	10,209	10,263	8,546	8,829	24,600
Unfunded Loan Commitment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	8,434	6,254	6,263	5,203	4,037	11,021	10,031
Increase (decrease) in CECL reserve	841	2,180	(9)		1,166	(6,984)	990
Ending balance	9,275	8,434	6,254	6,263	5,203	4,037	11,021
Unfunded Loan Commitment | US Loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	6,323	4,281	4,072	3,420	2,854	7,169	6,953
Increase (decrease) in CECL reserve	527	2,042	209		566	(4,315)	216
Ending balance	6,850	6,323	4,281	4,072	3,420	2,854	7,169
Unfunded Loan Commitment | Non-U.S. Loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	2,111	1,973	2,191	1,783	1,140	3,772	2,994
Increase (decrease) in CECL reserve	314	138	(218)		643	(2,632)	778
Ending balance	2,425	2,111	1,973	2,191	1,783	1,140	3,772
Unique Loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	33,495	30,897	32,657	31,255	32,782	33,305	33,159
Increase (decrease) in CECL reserve	3,082	2,598	(1,760)		(1,527)	(523)	146
Ending balance	36,577	33,495	30,897	32,657	31,255	32,782	33,305
Unique Loans | Unfunded Loan Commitment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	0	0	0	43	80	84
Increase (decrease) in CECL reserve	0	0	0		(43)	(37)	(4)
Ending balance	0	0	0	0	0	43	80
Impaired loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	54,874	54,874	54,874	69,661	69,661	69,661	69,661
Increase (decrease) in CECL reserve	0	0	0		0	0	0
Ending balance	54,874	54,874	54,874	54,874	69,661	69,661	69,661
Impaired loans | Unfunded Loan Commitment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	0	0	0	0	0	0
Increase (decrease) in CECL reserve	0	0	0		0	0	0
Ending balance	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0