Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash Flows From Operating Activities:
Net income	$ 360,052	$ 485,534
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	43,124	36,250
Amortization of loans and advances to financial advisors and other employees	104,703	98,624
Amortization of premium on investment portfolio	7,444	9,795
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	22,736	27,478
Amortization of intangible assets	13,872	14,966
Deferred income taxes	(33,022)	(15,690)
Stock-based compensation	106,237	103,281
(Gains)/losses on sale of investments	(2,290)	14,933
Other, net	2,141	4,883
Receivables:
Brokerage clients	38,711	(79,193)
Brokers, dealers, and clearing organizations	56,477	32,800
Securities purchased under agreements to resell	(64,205)	38,026
Financial instruments owned, including those pledged	(269,580)	159,318
Loans originated as held for sale	(614,254)	(513,195)
Proceeds from mortgages held for sale	626,663	503,284
Loans and advances to financial advisors and other employees	(130,665)	(105,431)
Other assets	(31,913)	(68,435)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	(65,852)	(90,781)
Brokers, dealers, and clearing organizations	60,363	4,172
Drafts	(24,780)	(52,164)
Financial instruments sold, but not yet purchased	93,131	(118,436)
Other liabilities and accrued expenses	(74,940)	(190,216)
Net cash provided by operating activities	224,153	299,803
Cash Flows From Investing Activities:
Principal paydowns, calls, maturities, and sales of available-for-sale securities	112,928	287,460
Calls and principal paydowns of held-to-maturity securities	89,815	113,454
Sale or maturity of investments	15,694	12,761
Decrease/(increase) in loans held for investment, net	147,629	(4,075,687)
Payments for:
Purchase of fixed assets	(39,026)	(44,924)
Purchase of available-for-sale securities	(19,635)	(102,917)
Purchase of held-to-maturity securities	0	(754,306)
Purchase of investments	(15,272)	(13,450)
Acquisitions, net of cash received	(113,452)	(11,021)
Net cash provided by/(used in) investing activities	178,681	(4,588,630)
Cash Flows From Financing Activities:
Payment of contingent consideration	(6,045)	(11,303)
Increase/(decrease) in securities sold under agreements to repurchase	196,939	(127,769)
Increase in bank deposits, net	477,247	3,910,271
Increase in securities loaned	36,465	19,521
Tax payments related to shares withheld for stock-based compensation plans	(83,909)	(87,434)
Repurchase of common stock	(300,152)	(30,666)
Cash dividends on preferred stock	(27,961)	(27,961)
Cash dividends paid to common stock and equity-award holders	(123,582)	(100,538)
Net cash provided by financing activities	169,002	3,544,121
Effect of exchange rate changes on cash	914	41,461
Increase/(decrease) in cash, cash equivalents, and cash segregated for regulatory purposes	572,750	(703,245)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of period	2,229,002	2,149,657
Cash, cash equivalents, and cash segregated for regulatory purposes at end of period	2,801,752	1,446,412
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	104,569	162,681
Cash paid for interest	575,121	103,100
Noncash financing activities:
Unit grants, net of forfeitures	$ 179,078	$ 188,359