Strong but still have flabby arms

How long does it usually take before all the flab is gone from the arms. I have built alot of strength and can see a little tone in my arms, but they still have flab.

Am i doing something wrong? Does it just take time? ive been working out with you guys for almost 3 yrs and sometimes i feel like im just not getting there. I never realized how long it takes to burn off fat.