Fair Value Of Financial Instruments (Estimated Fair Values Of Financial Instruments Not Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities purchased under agreements to resell	[1]	$ 624,049	$ 699,900
Held-to-maturity securities		2,855,791	4,122,907	[2]
Securities sold under agreements to repurchase	[3]	564,892	535,394
Bank deposits		14,836,646	15,863,613
Senior notes		1,016,751	1,015,973
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash		840,819	1,916,841
Cash segregated for regulatory purposes		62,654	132,814
Securities purchased under agreements to resell		624,049	699,900
Held-to-maturity securities		2,855,791	4,122,907
Bank loans		9,223,031	8,565,347
Loans held for sale		265,330	205,557
Securities sold under agreements to repurchase		564,892	535,394
Bank deposits		13,849,447	14,661,996
Federal Home Loan Bank advances		250,000	540,000
Borrowings		150	180,655
Senior notes		1,068,923	989,790
Debentures to Stifel Financial Capital Trusts		43,570	49,747
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash		840,819	1,916,841
Cash segregated for regulatory purposes		62,654	132,814
Securities purchased under agreements to resell		541,495	645,632
Securities sold under agreements to repurchase		19,175	87,273
Federal Home Loan Bank advances		250,000	540,000
Borrowings		150	180,655
Senior notes		1,068,923	989,790
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities purchased under agreements to resell		82,554	54,268
Held-to-maturity securities		2,690,211	3,960,099
Bank loans		9,223,031	8,565,347
Loans held for sale		265,330	205,557
Securities sold under agreements to repurchase		545,717	448,121
Bank deposits		13,849,447	14,661,996
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity securities		165,580	162,808
Debentures to Stifel Financial Capital Trusts		$ 43,570	$ 49,747

[1] Collateral received includes securities received by our company from the counterparty. These securities are not included on the consolidated statements of financial condition unless there is an event of default. The fair value of securities pledged as collateral was $623.2 million and $695.6 million at September 30, 2019 and December 31, 2018, respectively.

[2] Held-to-maturity securities are carried in the consolidated statements of financial condition at amortized cost, and the changes in the value of these securities, other than impairment charges, are not reported on the consolidated financial statements.

[3] Collateral pledged includes the fair value of securities pledged by our company to the counterparty. These securities are included in the consolidated statements of financial condition unless we default. Collateral pledged by our company to the counterparty includes U.S. government agency securities, U.S. government securities, and corporate fixed income securities with market values of $586.9 million and $558.6 million at September 30, 2019 and December 31, 2018, respectively.