Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash Flows From Operating Activities:
Net income	$ 328,869	$ 291,891
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	32,372	28,891
Amortization of loans and advances to financial advisors and other employees	76,901	69,955
Amortization of premium on investment portfolio	4,484	5,037
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	8,222	12,744
Amortization of intangible assets	11,838	9,070
Deferred income taxes	(21,336)	(4,789)
Stock-based compensation	85,189	75,878
Losses/(gains) on sale of investments	443	(1,363)
Gain on sale of leased aircraft engines	(19,763)	0
Other, net	(4,476)	3,060
Receivables:
Brokerage clients	877	29,485
Brokers, dealers, and clearing organizations	(11,074)	113,658
Securities purchased under agreements to resell	(89,690)	(194,420)
Financial instruments owned, including those pledged	(342,475)	(413,146)
Loans originated as held for sale	(1,030,487)	(484,273)
Proceeds from loans held for sale	883,018	500,067
Loans and advances to financial advisors and other employees	(127,006)	(81,128)
Other assets	19,821	(52,896)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	(226,068)	109,875
Brokers, dealers, and clearing organizations	(59,998)	51,856
Drafts	(38,975)	(16,064)
Financial instruments sold, but not yet purchased	136,570	210,670
Other liabilities and accrued expenses	(19,738)	(270,368)
Net cash used in operating activities	(402,482)	(6,310)
Cash Flows From Investing Activities:
Principal paydowns, calls, maturities, and sales of available-for-sale securities	115,288	79,339
Calls and principal paydowns of held-to-maturity securities	702,309	38,800
Sale or maturity of investments	5,203	1,794
Sale of leased aircraft engines	36,978	0
Decrease in loans held for investment, net	61,465	30,655
Payments for:
Purchase of fixed assets	(43,588)	(26,749)
Purchase of available-for-sale securities	(162,756)	(18,444)
Purchase of held-to-maturity securities	(872,900)	0
Purchase of investments	(5,670)	(11,554)
Acquisitions, net of cash received	(752)	(60,285)
Net cash provided by/(used in) investing activities	(164,423)	33,556
Cash Flows From Financing Activities:
Payment of contingent consideration	(753)	(919)
Increase in securities sold under agreements to repurchase	177,176	106,310
Decrease in bank deposits, net	(194,826)	(112,304)
Increase in securities loaned	21,109	42,071
Tax payments related to shares withheld for stock-based compensation plans	(102,231)	(80,656)
Repurchase of common stock	(78,307)	(181,342)
Cash dividends on preferred stock	(18,641)	(18,640)
Cash dividends paid to common stock and equity-award holders	(101,293)	(85,856)
Net cash used in financing activities	(297,766)	(331,336)
Effect of exchange rate changes on cash	(2,218)	4,386
Decrease in cash, cash equivalents, and cash segregated for regulatory purposes	(866,889)	(299,704)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of period	3,523,849	2,229,002
Cash, cash equivalents, and cash segregated for regulatory purposes at end of period	2,656,960	1,929,298
Supplemental disclosure of cash flow information:
Cash paid for interest	507,624	352,657
Cash paid for income taxes, net of refunds	150,990	95,244
Noncash financing activities:
Unit grants, net of forfeitures	$ 148,501	$ 168,545