Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows From Operating Activities:
Net income	$ 319,318	$ 279,906
Adjustments to reconcile net income to net cash provided by/(used in) operating activities:
Depreciation and amortization	28,930	20,503
Amortization of loans and advances to financial advisors and other employees	69,286	61,783
Amortization of premium on investment portfolio	26,687	18,714
Provision for loan losses and allowance for loans and advances to financial advisors and other employees	5,837	13,980
Amortization of intangible assets	10,960	8,741
Deferred income taxes	(13,573)	718
Stock-based compensation	78,329	75,382
(Gains)/losses on sale of investments	(1,279)	10,442
Other, net	(32,062)	(86,576)
Receivables:
Brokerage clients	(194,655)	(82,568)
Brokers, dealers, and clearing organizations	(156,658)	(187,013)
Securities purchased under agreements to resell	75,851	(110,141)
Financial instruments owned, including those pledged	110,240	(19,048)
Loans originated as held for sale	(1,293,650)	(1,099,187)
Proceeds from mortgages held for sale	1,255,823	1,051,789
Loans and advances to financial advisors and other employees	(147,144)	(67,872)
Other assets	(41,002)	31,543
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	69,761	(200,461)
Brokers, dealers, and clearing organizations	56,711	180,463
Drafts	(20,072)	(15,404)
Financial instruments sold, but not yet purchased	(41,565)	132,511
Other liabilities and accrued expenses	(132,768)	(66,290)
Net cash provided by/(used in) operating activities	33,305	(48,085)
Cash Flows From Investing Activities:
Principal paydowns, sales, calls, and maturities of available-for-sale securities	1,034,741	763,982
Calls and principal paydowns of held-to-maturity securities	456,804	443,295
Sale of other real estate owned	7,300
Sale or maturity of investments	4,263	24,345
Increase in bank loans, net	(592,547)	(810,798)
Payments for:
Purchase of fixed assets	(116,307)	(18,271)
Purchase of available-for-sale securities	(239,155)	(331,657)
Purchase of held-to-maturity securities	(243,335)	(1,313,587)
Purchase of investments	(9,100)	(7,578)
Acquisitions, net of cash received	(136,196)	599
Net cash provided by/(used in) investing activities	166,468	(1,249,670)
Cash Flows From Financing Activities:
Repayments of borrowings, net	(62,810)	(257,197)
(Repayments of)/proceeds from Federal Home Loan Bank advances, net	(290,000)	309,050
Payment of contingent consideration	(6,925)	(11,909)
Increase in securities sold under agreements to repurchase	5,189	261,780
(Decrease)/increase in bank deposits, net	(1,026,967)	590,000
Increase in securities loaned	124,707	471,367
Tax payments related to shares withheld for stock-based compensation plans	(30,425)	(39,815)
Proceeds from preferred stock issuance, net	154,988
Proceeds from non-controlling interests	26,800
Proceeds from stock option exercises		2,278
Repurchase of common stock	(180,434)	(62,514)
Cash dividends on preferred stock	(12,476)	(7,031)
Cash dividends paid to common stock and equity-award holders	(31,697)	(26,023)
Other	(2,379)
Net cash (used in)/provided by financing activities	(1,332,429)	1,229,986
Effect of exchange rate changes on cash	(5,198)	(3,429)
Decrease in cash, cash equivalents, and cash segregated for regulatory purposes	(1,137,854)	(71,198)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of period	2,069,374	787,085
Cash, cash equivalents, and cash segregated for regulatory purposes at end of period	931,520	715,887
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	110,907	27,280
Cash paid for interest	149,984	111,832
Noncash financing activities:
Unit grants, net of forfeitures	$ 128,539	119,051
Issuance of common stock for acquisitions		$ 110,671