Parent Company Only and PSLS - Condensed Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 383,098	$ 365,624	$ 970,965	$ 507,935
Other assets	85,955	106,025
Total assets	2,140,983	2,181,557
Liabilities and Shareholders' Equity
Short-term financing	30,000	0
Long-term financing	0	125,000
Accrued compensation	486,145	565,738
Other liabilities and accrued expenses	81,679	61,562
Total liabilities	841,510	927,529
Shareholders' equity	1,085,498	1,054,073
Total liabilities and shareholders' equity	2,140,983	2,181,557
Parent Company
Assets
Cash and cash equivalents	100	200	$ 200	$ 200
Investment in and advances to subsidiaries	1,147,090	1,221,123
Other assets	14,346	10,435
Total assets	1,161,536	1,231,758
Liabilities and Shareholders' Equity
Short-term financing	30,000	0
Long-term financing	0	125,000
Accrued compensation	42,698	48,414
Other liabilities and accrued expenses	3,340	4,271
Total liabilities	76,038	177,685
Shareholders' equity	1,085,498	1,054,073
Total liabilities and shareholders' equity	$ 1,161,536	$ 1,231,758