The detection of moving targets by radar in the presence of impulse interference is highly difficult. There are many papers, in which different Constant False Alarm Rate (CFAR) detectors have been analyzed in the presence of randomly arriving impulse interference. In this research, the randomly arriving impulse interference is mathematically described as Poisson and Binominal pulse sequences. These models of impulse noise are used for numerical analysis of excision (EXC) CFAR and EXC CFAR BI (binary integration) detectors. The analytical expressions for detection probabilities and the average decision threshold (ADT) of EXC CFAR detector in the presence of Poisson and Binomial distributed impulse interference are obtained and compared in the paper. These results can be used in the design of real radar systems.