Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income applicable to Stifel Financial Corp.	$ 109,414	$ 103,858	$ 317,706	$ 279,906
Preferred dividends	4,844	2,343	12,476	7,031
Net income available to common shareholders	$ 104,570	$ 101,515	$ 305,230	$ 272,875
Average shares used in basic computation	71,197	71,919	72,512	71,824
Dilutive effect of stock options and units	6,947	9,565	6,314	9,601
Average shares used in diluted computation	78,144	81,484	78,826	81,425
Basic	$ 1.47	$ 1.41	$ 4.21	$ 3.80
Diluted	$ 1.34	$ 1.25	$ 3.87	$ 3.35