In right $\triangle{ABC}$, shown here, AC = 24 units and BC = 7 units. Point D lies on $\overline{AB}$ so that $\overline{CD} \perp \overline{AB}$. The bisector of the smallest angle of $\triangle{ABC}$ intersects $\overline{CD}$ at point E. What is the length of $\overline{ED}$ ? Express your answer as a common fraction.