Business Changes and Developments - Goodwill Associated with Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Balance at beginning of period	$ 124,452	$ 125,493
Foreign Currency Translation and Other	4,110	(1,041)
Goodwill, Acquired During Period	102,221
Balance at end of period	230,783	124,452
Goodwill, Impaired, Accumulated Impairment Loss	38,528	38,528	$ 38,528
Goodwill, Gross	269,311	162,980	$ 164,021
Investment Banking & Equities
Goodwill [Roll Forward]
Balance at beginning of period	116,925	117,966
Foreign Currency Translation and Other	4,110	(1,041)
Goodwill, Acquired During Period	102,221
Balance at end of period	223,256	116,925
Investment Management
Goodwill [Roll Forward]
Balance at beginning of period	7,527	7,527
Foreign Currency Translation and Other	0	0
Goodwill, Acquired During Period	0
Balance at end of period	$ 7,527	$ 7,527