Derivatives - Fair Values of Derivatives Reported on Condensed Consolidated Statements of Financial Condition (Detail) - USD ($) $ in Thousands		Sep. 30, 2022	Dec. 31, 2021
Derivatives Fair Value [Line Items]
Derivative Assets, Fair Value		$ 25,182	$ 2,057
Derivative Assets, Notional		233,309	273,947
Derivative Liabilities, Fair Value		311,276	383,352
Derivative Liabilities, Notional		591,778	571,234
Derivative Assets, Fair Value, Counterparty and cash collateral netting		18,502	922
Derivative Assets, Fair Value, Total		18,502	922
Derivative Liabilities, Fair Value, Counterparty and cash collateral netting		311,145	372,245
Derivative Liabilities, Fair Value, Amounts not netted, Cash collateral	[1]	(2,363)	(2,476)
Derivative Liabilities, Fair Value, Total		308,782	369,378
Derivative Liabilities, Fair Value, Amounts not netted, Securities collateral	[1]		(391)
Forward Foreign Currency Exchange Rate Contracts [Member]
Derivatives Fair Value [Line Items]
Derivative Assets, Fair Value		967	1,005
Derivative Assets, Notional		96,733	253,059
Derivative Liabilities, Fair Value		3,437	761
Derivative Liabilities, Notional		231,388	174,550
Derivative Assets, Fair Value, Counterparty and cash collateral netting		(27)	(83)
Derivative Liabilities, Fair Value, Counterparty and cash collateral netting		(27)	(83)
Total Return Swaps and Other [Member]
Derivatives Fair Value [Line Items]
Derivative Assets, Fair Value		24,215	1,052
Derivative Assets, Notional		136,576	20,888
Derivative Liabilities, Fair Value		104	13,709
Derivative Liabilities, Notional		6,311	83,706
Derivative Assets, Fair Value, Counterparty and cash collateral netting		(6,653)	(1,052)
Derivative Liabilities, Fair Value, Counterparty and cash collateral netting		(104)	(11,024)
LGAC Warrants [Member]
Derivatives Fair Value [Line Items]
Derivative Liabilities, Fair Value		575	10,005
Derivative Liabilities, Notional		11,500	11,500
LFI and Other Similar Deferred Compensation Arrangements [Member]
Derivatives Fair Value [Line Items]
Derivative Liabilities, Fair Value		307,160	358,877
Derivative Liabilities, Notional		342,579	301,478
Derivative Liabilities, Fair Value, Counterparty and cash collateral netting		307,160	358,877
Total in "other assets" and "other liabilities" [Member]
Derivatives Fair Value [Line Items]
Derivative Assets, Fair Value, Counterparty and cash collateral netting		18,502	922
Derivative Liabilities, Fair Value, Counterparty and cash collateral netting		$ 311,145	$ 372,245

[1] Amounts are subject to master netting arrangements but do not meet the criteria for netting on the condensed consolidated statements of financial condition under U.S. GAAP. For some counterparties, the collateral amounts of securities and cash collateral pledged may exceed the derivative assets and derivative liabilities balances. Where this is the case, the total amount reported is limited to the net derivative assets and net derivative liabilities balances with that counterparty.