You say you are the ideal weight for your height. I'm assuming you mean according to the BMI measure. Your example would be the other reason I dislike that measure. BMI is a general indicator of someone who would be obese or underweight. It is by no means accurate, nor does it take into account your body fat.
So, while you can't target where your body burns fat, what you can do is change the proportions of muscle and fat at your weight. Your body is really good at maintaining weight, so that's the easy part.
For you I would recommend exercise. Do something you love that will challenge your muscles. Challenging the muscles causes them to grow, and since you'll be using more energy you'll have less fat to boot. In essence, you'll be lean but muscular.
Here's some potential ideas:
- Kayaking (a friend of mine loves this)
- Rock climbing
- Running (you'll lose fat, but you're only going to put muscle on where you use it--your legs)
- Strength training
- Martial arts
And the list goes on. Since you aren't trying to lose weight, you probably won't have to do too much to your diet. Now it's just about getting active.