I don't know that Islam's Allah would be considered an idol since there is no image.
1 Cor 10: 19Do I mean then that food sacrificed to an idol is anything, or that an idol is anything? 20No, but the sacrifices of pagans are offered to demons, not to God, and I do not want you to be participants with demons.
There are so many idols but some idols are not just objects that can not listen or talk, some idols are actually demons.