Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net income applicable to Stifel Financial Corp.	$ 86,589	$ 99,207
Preferred dividends	4,844	2,344
Net income available to common shareholders	$ 81,745	$ 96,863
Average shares used in basic computation	71,286	71,700
Dilutive effect of stock options and units	5,333	7,510
Average shares used in diluted computation	76,619	79,210
Basic	$ 1.15	$ 1.35
Diluted	$ 1.07	$ 1.22