An 'idol' is someone or something that is deeply cherished. What you are describing is an idol, some examples may include:
Movie stars or singers.
Devoted family members or loved ones.
Religious figures.
or even cherished possessions.
An 'ideal' is a sort of standard of perfection and can include someone or something that embodies perfection,or a personal endeavor . For example:
You unwilling to compromise your ideals.
He was an ideal father.
The situation was ideal.
Someone you idolize may be an ideal person to you, but the words are not interchangeable.