Islam, from what the believers have told me, is more a way of life than anything. Islam is unique in that the Koran puts forth morals and rules for everyday life and permeates even the most secular of acts. Mortgages, Politics, Finance, Marriage, Justice, Ethics – Islam permeates the whole culture.
So you would be correct to say that Islam is a political philosophy but only because it is a way of life. Catholicism, too, is a political philosophy because it wants Catholics to vote in a certain way…for the pro-life candidate, for the candidate who supports traditional marriage…whatever it is.