Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities:
Net income	$ 449,986	$ 393,968	$ 182,871
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	38,369	27,896	32,495
Amortization of loans and advances to financial advisors and other employees	95,053	85,374	91,594
Amortization of premium on investment portfolio	34,229	25,307	15,837
Provision for loan losses and allowance for loans and advances to financial advisors and other employees	11,007	19,601	25,985
Amortization of intangible assets	16,015	12,557	12,135
Deferred income taxes	(6,863)	14,254	118,129
Stock-based compensation	102,190	100,789	140,461
(Gain)/losses on sale of investments	(7,922)	22,780	(2,359)
Other, net	(38,554)	(10,723)	3,037
Receivables:
Brokerage clients, net	(17,487)	182,619	31,840
Brokers, dealers, and clearing organizations	(8,655)	(56,467)	566,454
Securities purchased under agreements to resell	314,892	(187,680)	(263,632)
Financial instruments owned, including those pledged	335,548	(123,765)	(217,386)
Loans originated as held for sale	(1,848,568)	(1,341,108)	(1,564,386)
Proceeds from mortgages held for sale	1,782,455	1,345,109	1,558,327
Loans and advances to financial advisors and other employees	(210,646)	(116,921)	(72,215)
Other assets	(36,290)	(1,562)	(113,875)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	(210,712)	9,173	(13,808)
Brokers, dealers, and clearing organizations	63,822	(16,383)	(79,905)
Drafts	14,871	(2,156)	12,592
Financial instruments sold, but not yet purchased	(284,510)	168,443	79,831
Other liabilities and accrued expenses	38,631	(21,579)	135,894
Net cash provided by operating activities	626,861	529,526	679,916
Cash Flows From Investing Activities:
Maturities, calls, sales, and principal paydowns of available-for-sale securities	1,224,619	1,244,434	985,520
Calls and principal paydowns of held-to-maturity securities	482,079	827,905	370,019
Sale of equipment		21,699
Sale or maturity of investments	14,699	24,445	28,839
Sale of other real estate owned	8,950
Increase in loans held for investment, net	(1,208,817)	(1,079,546)	(1,374,959)
Payments for:
Purchase of available-for-sale securities	(239,965)	(550,162)	(1,583,369)
Purchase of held-to-maturity securities	(243,335)	(1,352,587)	(1,033,700)
Purchase of investments	(37,563)	(8,828)	(4,296)
Purchase of fixed assets	(157,897)	(108,207)	(28,217)
Acquisitions, net of cash acquired	(193,097)	(8,394)	(7,220)
Net cash used in investing activities	(350,327)	(989,241)	(2,647,383)
Cash Flows from Financing Activities:
Repayments of borrowings, net	(62,810)	(216,572)	(121,000)
Proceeds from issuance of senior notes, net			217,913
Proceeds from advances from the FHLB, net			245,000
Repayments of advances from the FHLB, net	(290,000)	(214,950)
Proceeds from non-controlling interests	26,800	30,000
Proceeds from preferred stock issuance, net	154,988
(Decrease)/increase in securities sold under agreements to repurchase	(168,069)	301,690	(34,842)
(Decrease)/increase in bank deposits, net	(531,032)	1,950,661	1,884,452
Increase/(decrease) in securities loaned	114,135	172,380	(166,900)
Tax payments related to shares withheld for stock-based compensation plans	(33,268)	(43,229)	(214,744)
Proceeds from stock option exercises		2,278
Repurchase of common stock	(215,430)	(170,204)	(12,998)
Cash dividends on preferred stock	(17,319)	(9,375)	(9,375)
Cash dividends paid to common stock and equity-award holders	(41,948)	(34,638)	(13,688)
Extinguishment of Stifel Financial Capital Trust		(7,500)
Payment of contingent consideration	(9,526)	(12,846)	(13,328)
Other	(3,391)
Net cash (used in)/provided by financing activities	(1,076,870)	1,747,695	1,760,490
Effect of exchange rate changes on cash	4,932	(5,691)	7,895
(Decrease)/increase in cash, cash equivalents, and cash segregated for regulatory purposes	(795,404)	1,282,289	(199,082)
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of year	2,069,374	787,085	986,167
Cash, cash equivalents, and cash segregated for regulatory purposes at end of year	1,273,970	2,069,374	787,085
Supplemental disclosure of cash flow information:
Cash paid for interest	183,012	169,724	69,781
Cash paid for income taxes, net of refunds	161,926	67,379	21,516
Noncash investing and financing activities:
Unit grants, net of forfeitures	$ 139,408	136,529	71,300
Issuance of common stock for acquisitions		$ 110,671	$ 9,352