Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash Flows From Operating Activities:
Net income	$ 487,374	$ 360,052
Adjustments to reconcile net income to net cash (used in)/provided by operating activities:
Depreciation and amortization	47,487	43,124
Amortization of loans and advances to financial advisors and other employees	115,803	104,703
Amortization of premium on investment portfolio	6,442	7,444
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	13,509	22,736
Amortization of intangible assets	17,710	13,872
Deferred income taxes	(43,545)	(33,022)
Stock-based compensation	118,447	106,237
Unrealized gains on sale of investments	(311)	(2,290)
Gain on sale of leased aircraft engines	(20,816)	0
Other, net	(2,435)	2,141
Receivables:
Brokerage clients	(75,475)	38,711
Brokers, dealers, and clearing organizations	(145,855)	56,477
Securities purchased under agreements to resell	(315,218)	(64,205)
Financial instruments owned, including those pledged	(398,350)	(269,580)
Loans originated as held for sale	(1,531,378)	(614,254)
Proceeds from loans held for sale	1,383,014	626,663
Loans and advances to financial advisors and other employees	(141,509)	(130,665)
Other assets	114,950	(31,913)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	(66,024)	(65,852)
Brokers, dealers, and clearing organizations	(38,031)	60,363
Drafts	16,742	(24,780)
Financial instruments sold, but not yet purchased	236,961	93,131
Other liabilities and accrued expenses	16,363	(74,940)
Net cash (used in)/provided by operating activities	(204,145)	224,153
Cash Flows From Investing Activities:
Principal paydowns, calls, maturities, and sales of available-for-sale securities	206,665	112,928
Calls and principal paydowns of held-to-maturity securities	1,537,637	89,815
Sale or maturity of investments	5,204	15,694
Sale of leased aircraft engines	44,248	0
(Increase)/decrease in loans held for investment, net	(764,645)	147,629
Payments for:
Purchase of fixed assets	(56,357)	(39,026)
Purchase of available-for-sale securities	(237,640)	(19,635)
Purchase of held-to-maturity securities	(2,262,874)	0
Purchase of investments	(8,098)	(15,272)
Acquisitions, net of cash received	(8,106)	(113,452)
Net cash (used in)/provided by investing activities	(1,543,966)	178,681
Cash Flows From Financing Activities:
Payment of contingent consideration	(902)	(6,045)
Increase in securities sold under agreements to repurchase	240,340	196,939
Increase in bank deposits, net	785,939	477,247
Increase in securities loaned	16,562	36,465
Tax payments related to shares withheld for stock-based compensation plans	(104,029)	(83,909)
Repayment of senior notes	(500,000)	0
Repurchase of common stock	(98,529)	(300,152)
Cash dividends on preferred stock	(27,961)	(27,961)
Cash dividends paid to common stock and equity-award holders	(144,638)	(123,582)
Net cash provided by financing activities	166,782	169,002
Effect of exchange rate changes on cash	2,766	914
(Decrease)/increase in cash, cash equivalents, and cash segregated for regulatory purposes	(1,578,563)	572,750
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	1,945,286	2,801,752
Supplemental disclosure of cash flow information:
Cash paid for interest	763,539	575,121
Cash paid for income taxes, net of refunds	185,354	104,569
Noncash financing activities:
Unit grants, net of forfeitures	$ 157,748	$ 179,078