Fair Value Of Financial Instruments (Estimated Fair Values Of Financial Instruments Not Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands		Jun. 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]	$ 596,572	$ 699,900
Held-to-maturity securities	[2]	3,946,782	4,122,907
Securities sold under agreements to repurchase	[3]	762,282	535,394
Bank deposits		14,901,061	15,863,613
Borrowings		117,845	180,655
Senior notes		1,016,492	1,015,973
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash		765,767	1,916,841
Cash segregated for regulatory purposes		21,231	132,814
Securities purchased under agreements to resell		596,572	699,900
Held-to-maturity securities		3,946,782	4,122,907
Bank loans		9,057,908	8,565,347
Loans held for sale		163,511	205,557
Securities sold under agreements to repurchase		762,282	535,394
Bank deposits		14,020,564	14,661,996
Federal Home Loan Bank advances		250,000	540,000
Borrowings		117,845	180,655
Senior notes		1,047,702	989,790
Debentures to Stifel Financial Capital Trusts		45,740	49,747
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash		765,767	1,916,841
Cash segregated for regulatory purposes		21,231	132,814
Securities purchased under agreements to resell		539,265	645,632
Securities sold under agreements to repurchase		98,626	87,273
Federal Home Loan Bank advances		250,000	540,000
Borrowings		117,845	180,655
Senior notes		1,047,702	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		57,307	54,268
Held-to-maturity securities		3,779,407	3,960,099
Bank loans		9,057,908	8,565,347
Loans held for sale		163,511	205,557
Securities sold under agreements to repurchase		663,656	448,121
Bank deposits		14,020,564	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		167,375	162,808
Debentures to Stifel Financial Capital Trusts		$ 45,740	$ 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 $597.5 million and $695.6 million at June 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 $796.3 million and $558.6 million at June 30, 2019 and December 31, 2018, respectively.