Fair Value Of Financial Instruments (Estimated Fair Values Of Financial Instruments Not Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities purchased under agreements to resell		$ 807,664	$ 579,866
Held-to-maturity securities	[1]	5,251,532	5,343,481
Securities sold under agreements to repurchase		530,195	385,528
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash		1,551,763	1,960,322
Cash segregated for regulatory purposes		169,337	186,331
Securities purchased under agreements to resell		807,664	579,866
Held-to-maturity securities		5,251,532	5,343,481
Bank loans		17,528,412	16,704,912
Loans held for sale		315,427	207,715
Securities sold under agreements to repurchase		530,195	385,528
Bank deposits		23,793,441	22,998,842
Federal Home Loan Bank advances		28,000
Senior notes		1,141,798	1,218,344
Debentures to Stifel Financial Capital Trusts		50,666	46,340
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash		1,551,763	1,960,322
Cash segregated for regulatory purposes		169,337	186,331
Securities purchased under agreements to resell		534,648	371,797
Securities sold under agreements to repurchase		57,928	10,000
Federal Home Loan Bank advances		28,000
Senior notes		1,141,798	1,218,344
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		273,016	208,069
Held-to-maturity securities		5,125,933	5,205,085
Bank loans		17,528,412	16,704,912
Loans held for sale		315,427	207,715
Securities sold under agreements to repurchase		472,267	375,528
Bank deposits		23,793,441	22,998,842
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		125,599	138,396
Debentures to Stifel Financial Capital Trusts		$ 50,666	$ 46,340

[1] 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.