Contours of mean growth rate plotted as a function of normalized rotation rate n_Ω∥ = Ω_∥/ω_A,φ and the relative magnetic diffusion n_η = η/η_crit. The white region represents stability, for at least 100τ_A. The color contours correspond to increasing growth rates of the instability, where black corresponds to small and blue to fast growth rates. The yellow dashed line corresponds to the relation n_Ω∥ = 2n_η + 1 separating the stable and unstable regions.