A plant is governed by the transfer function $G(s) = \\frac{1}{(s+1)(s+2)}$. Under proportional feedback control with gain $K_p$, the closed-loop system has the transfer function $T(s) = \\frac{K_p}{s^2 + 3s + (2 + K_p)}$. For what range of $K_p$ is the closed-loop system stable?