Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Amortized Cost	$ 462,544	$ 706,826
Accounts Receivable, Allowances	1,447	2,704
Furniture, Equipment and Leasehold Improvements, Accumulated Depreciation and Amortization	176,376	165,857
Intangible Assets, Accumulated Amortization	$ 3,476	$ 3,294
Treasury Stock at Cost, shares	40,460,685	36,900,858
Class A [Member]
Common Stock, Par Value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Issued	79,597,763	74,804,288
Common Stock, Shares, Outstanding	39,137,078	37,903,430
Class B [Member]
Common Stock, Par Value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000	1,000,000
Common Stock, Shares, Issued	50	53
Common Stock, Shares, Outstanding	50	53