Ignoring the whole .idea folder is not necessarily the best idea. There’s a number of similar discussions here about this.
- How to deal with IntelliJ IDEA project files under Git source control constantly changing?
- Intellij Idea 9/10, what folders to check into (or not check into) source control?
- Should the .idea folder be kept under source control?
But I suggest to check the official FAQ on this matter.