Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Cash Flows From Operating Activities:
Net income	$ 208,047	$ 328,869
Adjustments to reconcile net income to net cash provided by/(used in) operating activities:
Depreciation and amortization	30,281	32,372
Amortization of loans and advances to financial advisors and other employees	70,918	76,901
Amortization of premium on investment portfolio	3,660	4,484
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	20,348	8,222
Amortization of intangible assets	10,937	11,838
Deferred income taxes	(42,923)	(21,336)
Stock-based compensation	93,481	85,189
(Gains)/losses on sale of investments	(4,468)	443
Gain on sale of leased aircraft engines	(32,063)	(19,763)
Other, net	(2,101)	(4,476)
Receivables:
Brokerage clients	(19,799)	877
Brokers, dealers, and clearing organizations	(150,592)	(11,074)
Securities purchased under agreements to resell	(108,554)	(89,690)
Financial instruments owned	(174,505)	(342,475)
Loans originated as held for sale	(986,234)	(1,030,487)
Proceeds from loans held for sale	1,403,477	1,152,686
Loans and advances to financial advisors and other employees	(127,850)	(127,006)
Other assets	69,236	19,821
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	110,388	(226,068)
Brokers, dealers, and clearing organizations	11,310	(59,998)
Drafts	(20,047)	(38,975)
Financial instruments sold, but not yet purchased	173,284	136,570
Other liabilities and accrued expenses	(139,949)	(19,738)
Net cash provided by/(used in) operating activities	396,282	(132,814)
Cash Flows From Investing Activities:
Principal paydowns, maturities, and calls of available-for-sale securities	165,343	115,288
Principal paydowns, maturities, and calls of held-to-maturity securities	845,032	702,309
Sale or maturity of investments	8	5,203
Sale of leased aircraft engines	77,803	36,978
(Increase)/decrease in loans held for investment, net	(573,871)	(208,203)
Payments for:
Purchase of fixed assets	(31,405)	(43,588)
Purchase of available-for-sale securities	(90,408)	(162,756)
Purchase of held-to-maturity securities	(904,935)	(872,900)
Purchase of investments	(1,454)	(5,670)
Acquisitions, net of cash received	(72,591)	(752)
Net cash used in investing activities	(586,478)	(434,091)
Cash Flows From Financing Activities:
Payment of contingent consideration	(190)	(753)
Increase in securities sold under agreements to repurchase	139,262	177,176
Decrease in bank deposits, net	(429,164)	(194,826)
Increase in securities loaned	221,073	21,109
Repayment of short term debt	(75,056)	0
Tax payments related to shares withheld for stock-based compensation plans	(119,068)	(102,231)
Repurchase of common stock	(176,211)	(78,307)
Cash dividends on preferred stock	(18,641)	(18,641)
Cash dividends paid to common stock and equity-award holders	(115,557)	(101,293)
Net cash used in financing activities	(573,552)	(297,766)
Effect of exchange rate changes on cash	11,608	(2,218)
Decrease in cash, cash equivalents, and cash segregated for regulatory purposes	(752,140)	(866,889)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of period	2,678,203	3,523,849
Cash, cash equivalents, and cash segregated for regulatory purposes at end of period	1,926,063	2,656,960
Supplemental disclosure of cash flow information:
Cash paid for interest	426,513	507,624
Cash paid for income taxes, net of refunds	81,595	150,990
Noncash investing and financing activities:
Transfer of loans held for investment to held for sale	638,165	155,651
Unit grants, net of forfeitures	$ 228,370	$ 148,501