Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities:
Net income	$ 503,472	$ 449,986	$ 393,968
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,863	38,369	27,896
Amortization of loans and advances to financial advisors and other employees	103,983	95,053	85,374
Amortization of premium on investment portfolio	20,739	34,229	25,307
Provision for credit losses and allowance for loans and advances to financial advisors and other employees	33,925	11,007	19,601
Amortization of intangible assets	19,620	16,015	12,557
Deferred income taxes	(39,071)	(6,863)	14,254
Stock-based compensation	108,217	102,190	100,789
Unrealized losses/(gains) on investments	18,908	(7,922)	22,780
Other, net	(10,326)	(38,554)	(10,723)
Receivables:
Brokerage clients, net	415,286	(17,487)	182,619
Brokers, dealers, and clearing organizations	78,298	(8,655)	(56,467)
Securities purchased under agreements to resell	167,078	314,892	(187,680)
Financial instruments owned, including those pledged	278,904	335,548	(123,765)
Loans originated as held for sale	(3,019,290)	(1,848,568)	(1,341,108)
Proceeds from mortgages held for sale	2,894,742	1,782,455	1,345,109
Loans and advances to financial advisors and other employees	(179,995)	(210,646)	(116,921)
Other assets	(117,471)	(36,290)	(1,562)
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	323,493	(210,712)	9,173
Brokers, dealers, and clearing organizations	(71,144)	63,822	(16,383)
Drafts	(2,021)	14,871	(2,156)
Financial instruments sold, but not yet purchased	(224,874)	(284,510)	168,443
Other liabilities and accrued expenses	318,480	38,631	(21,579)
Net cash provided by operating activities	1,661,816	626,861	529,526
Cash Flows From Investing Activities:
Maturities, calls, sales, and principal paydowns of available-for-sale securities	896,746	1,224,619	1,244,434
Calls and principal paydowns of held-to-maturity securities	159,964	482,079	827,905
Sale of equipment			21,699
Sale or maturity of investments	2,139	14,699	24,445
Sale of other real estate owned		8,950
Disposition of business	37,000
Increase in loans held for investment, net	(1,441,303)	(1,208,817)	(1,079,546)
Payments for:
Purchase of available-for-sale securities	(864,200)	(239,965)	(550,162)
Purchase of held-to-maturity securities	(384,700)	(243,335)	(1,352,587)
Purchase of investments	(21,317)	(37,563)	(8,828)
Purchase of fixed assets	(73,364)	(157,897)	(108,207)
Acquisitions, net of cash acquired	(280)	(193,097)	(8,394)
Net cash used in investing activities	(1,689,315)	(350,327)	(989,241)
Cash Flows from Financing Activities:
Repayments of borrowings, net		(62,810)	(216,572)
Repayments of senior notes	(300,000)
Proceeds from issuance of senior notes, net	394,030
Repayments of Federal Home Loan Bank advances, net	(250,000)	(290,000)	(214,950)
Proceeds from non-controlling interests		26,800	30,000
Proceeds from preferred stock issuance, net	217,995	154,988
(Decrease)/increase in securities sold under agreements to repurchase	(200,679)	(168,069)	301,690
Increase/(decrease) in bank deposits, net	2,063,916	(531,032)	1,950,661
(Decrease)/increase in securities loaned	(463,210)	114,135	172,380
Tax payments related to shares withheld for stock-based compensation plans	(75,838)	(33,268)	(43,229)
Proceeds from stock option exercises			2,278
Repurchase of common stock	(58,261)	(215,430)	(170,204)
Cash dividends on preferred stock	(27,261)	(17,319)	(9,375)
Cash dividends paid to common stock and equity-award holders	(46,497)	(41,948)	(34,638)
Cash paid to employees upon settlement of equity awards	(27,101)
Extinguishment of Stifel Financial Capital Trust			(7,500)
Payment of contingent consideration	(28,221)	(9,526)	(12,846)
Other		(3,391)
Net cash provided by/(used in) financing activities	1,198,873	(1,076,870)	1,747,695
Effect of exchange rate changes on cash	6,862	4,932	(5,691)
Increase/(decrease) in cash, cash equivalents, and cash segregated for regulatory purposes	1,178,236	(795,404)	1,282,289
Cash, cash equivalents, and cash segregated for regulatory purposes at beginning of year	1,273,970	2,069,374	787,085
Cash, cash equivalents, and cash segregated for regulatory purposes at end of year	2,452,206	1,273,970	2,069,374
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	160,007	161,926	67,379
Cash paid for interest	84,821	183,012	169,724
Noncash investing and financing activities:
Unit grants, net of forfeitures	$ 125,033	$ 139,408	136,529
Issuance of common stock for acquisitions			$ 110,671