  We consider four two-level atoms interacting with independent non-Markovian
reservoirs with detuning. We mainly investigate the effects of the detuning and
the length of the reservoir correlation time on the decoherence dynamics of the
multipartite entanglement. We find that the time evolution of the entanglement
of atomic and reservoir subsystems is determined by a parameter, which is a
function of the detuning and the reservoir correlation time. We also find that
the decay and revival of the entanglement of the atomic and reservoir
subsystems are closely related to the sign of the decay rate. We also show that
the cluster state is the most robust to decoherence comparing with Dicke, GHZ,
and W states for this decoherence channel
