Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash Flows From Operating Activities:
Net income	$ 157,539	$ 173,549
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	15,076	11,675
Amortization of loans and advances to financial advisors and other employees	34,057	32,849
Amortization of premium on investment portfolio	2,356	3,880
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	4,920	8,240
Amortization of intangible assets	4,437	5,094
Deferred income taxes	13,069	25,732
Stock-based compensation	43,083	45,502
Gains on sale of investments	(1,353)	(3,799)
Other, net	(6,157)	(3,666)
Receivables:
Brokerage clients	(34,435)	(167,365)
Brokers, dealers, and clearing organizations	(39,648)	(108,419)
Securities purchased under agreements to resell	(201,053)	(227,798)
Financial instruments owned, including those pledged	(242,050)	(122,632)
Loans originated as held for sale	(380,033)	(236,323)
Proceeds from mortgages held for sale	317,468	202,870
Loans and advances to financial advisors and other employees	(40,053)	(45,237)
Other assets	218	29,624
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	136,855	(62,495)
Brokers, dealers, and clearing organizations	3,369	115,682
Drafts	(21,883)	(33,389)
Financial instruments sold, but not yet purchased	199,064	185,265
Other liabilities and accrued expenses	(349,919)	(504,485)
Net cash used in operating activities	(385,073)	(675,646)
Cash Flows From Investing Activities:
Principal paydowns, calls, maturities, and sales of available-for-sale securities	47,416	80,221
Calls and principal paydowns of held-to-maturity securities	5,548	102,744
Sale or maturity of investments	0	10,092
Increase in loans held for investment, net	(250,052)	(1,039,983)
Payments for:
Purchase of fixed assets	(15,411)	(12,628)
Purchase of available-for-sale securities	(7,551)	(1,906)
Purchase of held-to-maturity securities	0	(70,000)
Purchase of investments	(10,919)	(4,235)
Acquisitions, net of cash received	(58,765)	0
Net cash used in investing activities	(289,734)	(935,695)
Cash Flows From Financing Activities:
Proceeds from Federal Home Loan Bank advances, net	0	28,000
Payment of contingent consideration	(5,037)	(5,974)
Increase In Securities Sold Under Agreements To Repurchase	217,715	144,667
Increase in bank deposits, net	1,208,216	915,278
Increase in securities loaned	32,868	223,717
Tax payments related to shares withheld for stock-based compensation plans	(74,238)	(84,259)
Repurchase of common stock	(94,521)	0
Cash dividends on preferred stock	(9,320)	(9,320)
Cash dividends paid to common stock and equity-award holders	(47,009)	(36,451)
Net cash provided by financing activities	1,228,674	1,175,658
Effect of exchange rate changes on cash	3,429	10,509
Increase/(decrease) in cash, cash equivalents, and cash segregated for regulatory purposes	557,296	(425,174)
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	2,786,298	1,724,483
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	4,037	9,806
Cash paid for interest	158,201	15,731
Noncash financing activities:
Unit grants, net of forfeitures	$ 143,638	$ 156,069