Derivatives - Offsetting of Derivative Instruments (Detail) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Offsetting Assets [Line Items]
Gross amounts, assets	$ 75,279,000	$ 70,033,000
Gross amounts offset, assets	(68,234,000)	(66,271,000)
Net amounts presented in the statements of financial condition, assets	7,045,000	3,762,000
Gross amounts, liabilities	75,802,000	73,904,000
Gross amounts offset, liabilities	(68,234,000)	(66,271,000)
Net amounts presented in the statements of financial condition, liabilities	7,568,000	7,633,000
Additional balance in gross amounts not offset	0	0
FX swaps
Offsetting Assets [Line Items]
Gross amounts, assets	6,994,000	3,623,000
Gross amounts offset, assets	(541,000)	(489,000)
Net amounts presented in the statements of financial condition, assets	6,453,000	3,134,000
Gross amounts, liabilities	6,203,000	6,285,000
Gross amounts offset, liabilities	(541,000)	(489,000)
Net amounts presented in the statements of financial condition, liabilities	5,662,000	5,796,000
Interest rate swaps
Offsetting Assets [Line Items]
Gross amounts, assets	19,710,000	895,000
Gross amounts offset, assets	(19,682,000)	(870,000)
Net amounts presented in the statements of financial condition, assets	28,000	25,000
Gross amounts, liabilities	19,682,000	870,000
Gross amounts offset, liabilities	(19,682,000)	(870,000)
Net amounts presented in the statements of financial condition, liabilities	0	0
Forwards
Offsetting Assets [Line Items]
Gross amounts, assets	588,000	746,000
Gross amounts offset, assets	(24,000)	(143,000)
Net amounts presented in the statements of financial condition, assets	564,000	603,000
Gross amounts, liabilities	1,001,000	712,000
Gross amounts offset, liabilities	(24,000)	(143,000)
Net amounts presented in the statements of financial condition, liabilities	977,000	569,000
Futures
Offsetting Assets [Line Items]
Gross amounts, assets	47,987,000	64,769,000
Gross amounts offset, assets	(47,987,000)	(64,769,000)
Net amounts presented in the statements of financial condition, assets	0	0
Gross amounts, liabilities	48,916,000	66,037,000
Gross amounts offset, liabilities	(47,987,000)	(64,769,000)
Net amounts presented in the statements of financial condition, liabilities	$ 929,000	$ 1,268,000