If you have reached your ideal weight then you know you're healthy. Every body has a different shape and it sounds like yours is thick. There's nothing wrong with that, and it is not going to change. You can, of course, do some exercise to slim your waist, for instance. You can polish your body if you work hard, but you're not going to become petite, that's something you need to accept. Personally, I'm on the thick side (besides of being overweight) and MY ideal weight is far above the ideal weight I'm supposed to be, because my bones are far too big for me to carry a small size and still look good.
But don't worry, if you go to a gym you can ask one of the trainers there, or you can get a personal trainer, or even look up exercises on the internet, that might help you slim those specific areas you mentioned.