Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income applicable to Stifel Financial Corp.	$ 109,085	$ 87,287	$ 208,292	$ 176,048
Preferred dividends	5,288	2,344	7,632	4,688
Net income available to common shareholders	$ 103,797	$ 84,943	$ 200,660	$ 171,360
Average shares used in basic computation	72,519	71,692	73,180	71,843
Dilutive effect of stock options and units	6,560	9,607	5,980	9,705
Average shares used in diluted computation	79,079	81,299	79,160	81,548
Basic	$ 1.43	$ 1.18	$ 2.74	$ 2.39
Diluted	$ 1.31	$ 1.04	$ 2.53	$ 2.10