Matrix A $\in$ $\mathbb{R}^{n\times n}$ is idempotent if $A^{2} = A$. Describe the Jordan form of A.

How do I do this?

I am able to decompose a matrix to its Jordan form given that the matrix contains numeric entries. But I am having hard time figuring out the correct way to approach the solution in a general case such as this question. Thanks!