Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows From Operating Activities:
Net income	$ 194,476	$ 209,196
Adjustments to reconcile net income to net cash provided by/(used in) operating activities:
Depreciation and amortization	19,235	20,410
Amortization of loans and advances to financial advisors and other employees	51,663	45,266
Amortization of premium on investment portfolio	11,119	15,083
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	36,142	4,838
Amortization of intangible assets	9,760	7,140
Deferred income taxes	2,756	511
Stock-based compensation	55,223	54,443
(Gains)/losses on sale of investments	27,758	(14,484)
Other, net	(8,203)	(25,671)
Receivables:
Brokerage clients	317,963	(145,463)
Brokers, dealers, and clearing organizations	44,332	(250,609)
Securities purchased under agreements to resell	(61,758)	103,328
Financial instruments owned, including those pledged	126,714	(52,227)
Loans originated as held for sale	(1,200,104)	(702,007)
Proceeds from mortgages held for sale	1,149,623	759,773
Loans and advances to financial advisors and other employees	(70,474)	(107,932)
Other assets	54,522	(48,951)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	242,006	(49,014)
Brokers, dealers, and clearing organizations	66,753	94,795
Drafts	(29,437)	(11,503)
Financial instruments sold, but not yet purchased	(64,530)	8,982
Other liabilities and accrued expenses	(75,538)	(226,315)
Net cash provided by/(used in) operating activities	900,001	(310,411)
Cash Flows From Investing Activities:
Principal paydowns, sales, calls, and maturities of available-for-sale securities	681,961	410,311
Calls and principal paydowns of held-to-maturity securities	155,461	256,404
Sale or maturity of investments	2,252	694
Disposition of business	37,000
Increase in loans held for investment, net	(875,299)	(454,048)
Payments for:
Purchase of fixed assets	(58,959)	(101,683)
Purchase of available-for-sale securities	(601,660)	(500)
Purchase of held-to-maturity securities	(384,700)
Purchase of investments	(12,900)
Acquisitions, net of cash received	(280)	(28,236)
Net cash (used in)/provided by investing activities	(1,057,124)	82,942
Cash Flows From Financing Activities:
Repayments of borrowings, net		(62,810)
Proceeds from/(repayments of) Federal Home Loan Bank advances, net	73,000	(290,000)
Payment of contingent consideration	(21,741)	(6,925)
(Decrease)/increase in securities sold under agreements to repurchase	(171,746)	202,579
Increase/(decrease) in bank deposits, net	970,240	(962,552)
(Decrease)/increase in securities loaned	(480,133)	100,086
Tax payments related to shares withheld for stock-based compensation plans	(69,574)	(28,992)
Proceeds from preferred stock issuance, net	217,980	154,988
Proceeds from issuance of senior notes, net	394,314
Proceeds from non-controlling interests		26,800
Repurchase of common stock	(56,517)	(124,966)
Cash dividends on preferred stock	(9,688)	(7,632)
Cash dividends paid to common stock and equity-award holders	(23,131)	(21,352)
Cash paid to employees upon settlement of equity awards	(27,101)
Other		(1,407)
Net cash provided by/(used in) financing activities	795,903	(1,022,183)
Effect of exchange rate changes on cash	(9,978)	(1,134)
Increase/(decrease) in cash, cash equivalents, and cash segregated for regulatory purposes	628,802	(1,250,786)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of period	1,273,970	2,069,374
Cash, cash equivalents, and cash segregated for regulatory purposes at end of period	1,902,772	818,588
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	19,528	84,806
Cash paid for interest	47,650	103,112
Noncash financing activities:
Unit grants, net of forfeitures	$ 113,268	$ 102,519