Derivatives - Offsetting of Derivative Instruments (Detail) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Offsetting Assets [Line Items]
Gross amounts, assets	$ 91,076,000	$ 70,033,000
Gross amounts offset, assets	(85,875,000)	(66,271,000)
Net amounts presented in the statements of financial condition, assets	5,201,000	3,762,000
Gross amounts, liabilities	89,875,000	73,904,000
Gross amounts offset, liabilities	(85,875,000)	(66,271,000)
Net amounts presented in the statements of financial condition, liabilities	4,000,000	7,633,000
Additional balance in gross amounts not offset	0	0
FX swaps
Offsetting Assets [Line Items]
Gross amounts, assets	4,642,000	3,623,000
Gross amounts offset, assets	(256,000)	(489,000)
Net amounts presented in the statements of financial condition, assets	4,386,000	3,134,000
Gross amounts, liabilities	2,790,000	6,285,000
Gross amounts offset, liabilities	(256,000)	(489,000)
Net amounts presented in the statements of financial condition, liabilities	2,534,000	5,796,000
Interest rate swaps
Offsetting Assets [Line Items]
Gross amounts, assets	15,693,000	895,000
Gross amounts offset, assets	(15,476,000)	(870,000)
Net amounts presented in the statements of financial condition, assets	217,000	25,000
Gross amounts, liabilities	15,476,000	870,000
Gross amounts offset, liabilities	(15,476,000)	(870,000)
Net amounts presented in the statements of financial condition, liabilities	0	0
Forwards
Offsetting Assets [Line Items]
Gross amounts, assets	649,000	746,000
Gross amounts offset, assets	(51,000)	(143,000)
Net amounts presented in the statements of financial condition, assets	598,000	603,000
Gross amounts, liabilities	1,160,000	712,000
Gross amounts offset, liabilities	(51,000)	(143,000)
Net amounts presented in the statements of financial condition, liabilities	1,109,000	569,000
Futures
Offsetting Assets [Line Items]
Gross amounts, assets	70,092,000	64,769,000
Gross amounts offset, assets	(70,092,000)	(64,769,000)
Net amounts presented in the statements of financial condition, assets	0	0
Gross amounts, liabilities	70,449,000	66,037,000
Gross amounts offset, liabilities	(70,092,000)	(64,769,000)
Net amounts presented in the statements of financial condition, liabilities	$ 357,000	$ 1,268,000