Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash Flows From Operating Activities:
Net income	$ 173,549	$ 173,015
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,675	10,907
Amortization of loans and advances to financial advisors and other employees	32,849	26,961
Amortization of premium on investment portfolio	3,880	4,498
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	8,240	(5,252)
Amortization of intangible assets	5,094	4,268
Deferred income taxes	25,732	47,253
Stock-based compensation	45,502	32,029
Gains on sale of investments	(3,799)	(4,284)
Other, net	(3,666)	26,582
Receivables:
Brokerage clients	(167,365)	(266,101)
Brokers, dealers, and clearing organizations	(108,419)	(12,940)
Securities purchased under agreements to resell	(227,798)	(252,095)
Financial instruments owned, including those pledged	(122,632)	(287,254)
Loans originated as held for sale	(236,323)	(754,317)
Proceeds from mortgages held for sale	202,870	952,053
Loans and advances to financial advisors and other employees	(45,237)	(30,700)
Other assets	46,390	(238,950)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	(62,495)	(178,278)
Brokers, dealers, and clearing organizations	115,682	44,423
Drafts	(33,389)	(39,591)
Financial instruments sold, but not yet purchased	185,265	206,784
Other liabilities and accrued expenses	(507,658)	20,804
Net cash provided by operating activities	(662,053)	(520,185)
Cash Flows From Investing Activities:
Principal paydowns, calls, and maturities of available-for-sale securities	80,221	128,302
Calls and principal paydowns of held-to-maturity securities	102,744	480,635
Sale or maturity of investments	10,092	1,108
Increase in loans held for investment, net	(1,039,983)	(1,079,671)
Payments for:
Purchase of fixed assets	(12,628)	(11,245)
Purchase of available-for-sale securities	(1,906)	(427,596)
Purchase of held-to-maturity securities	(70,000)	(811,473)
Purchase of investments	(4,235)	(2,675)
Acquisitions, net of cash received	0	(315)
Net cash used in investing activities	(935,695)	(1,722,930)
Cash Flows From Financing Activities:
Proceeds from Federal Home Loan Bank advances, net	28,000	0
Payment of contingent consideration	(5,974)	(10,480)
Increase in securities sold under agreements to repurchase	144,667	17,273
Increase in bank deposits, net	915,278	1,318,636
Increase in securities loaned	223,717	86,577
Tax payments related to shares withheld for stock-based compensation plans	(84,259)	(66,839)
Repurchase of common stock	0	(12,038)
Cash dividends on preferred stock	(9,320)	(8,289)
Cash dividends paid to common stock and equity-award holders	(36,451)	(15,682)
Net cash provided by financing activities	1,175,658	1,309,158
Effect of exchange rate changes on cash	(3,084)	2,336
Decrease in cash, cash equivalents, and cash segregated for regulatory purposes	(425,174)	(931,621)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of period	2,149,657	2,452,206
Cash, cash equivalents, and cash segregated for regulatory purposes at end of period	1,724,483	1,520,585
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	9,806	8,394
Cash paid for interest	15,731	15,610
Noncash financing activities:
Unit grants, net of forfeitures	$ 156,069	$ 128,639