Filament thickness distributions for decaying turbulence simulations at time t = 5 × 10^-3 using different timestep limits. The black solid line corresponds to the ideal 512³ run and the colored lines to runs with ambipolar diffusion and different timestep limits. t_a is the Alfvén crossing time of a cell. Top: density threshold of 2000 cm^-3, bottom: 5000 cm^-3. The dotted lines indicate the mean ambipolar diffusion dissipation length λ_d, calculated from Eq. (1) for each density threshold, the resolution lengths l_m,512 and l_m,1024, equal to the length of 20 cells, and the sonic length l_s, defined by Eq. (11), for an rms Mach number of 5.