How old do I have to be to move away from home without parental consent?

In Idaho, the legal age of majority is 18 and that is when a minor can move.

You can probably move, but watch what you ask for. Unless your parents are abusive, I would think long and hard about what you do. While you are a minor, you are asking to be treated like an adult. With that comes a lot of responsibility. As for your boyfriend.... how old is he?? Does he have a job? Can he support both of you?? ... especially if you don't have a high school diploma (which at your age, I doubt that you do). Do you have medical insurance?? What if you get pregnant?? Who pays for the cost of having the baby. And God forbid, what if the child is born with health issues?? Statistics show that is costs approximately $200,000.00 to raise a child from birth to age 18. Are you prepared for this???? If you end up pregnant, what is the likelihood that your boyfriend will kick you to the curb, and move on to the next woman, leaving you as a single, un-wed mother, without a high school education. There is more to a relationship than "being in love". This is NOT the time to think emotionally.

18 years old.

You cannot legally do so until you are 18 years old.

No. You can move when your 18 or have graduated from high school. Not before.