In this paper, the problem of noncoherently detecting binary data transmitted over channels with complex non-Gaussian fading statistics is considered. The results are obtained by employing a quasi-moment expansion technique. Numerical evaluation of the performance of an L-diversity FSK system is carried out for a non-Gaussian fading channel modeled by the Middleton Class A statistics. A two-term approximation is shown to provide good agreement with the exact computation that requires, in general, a complete statistical description of the channel.