A Change of Direction

I had an idea for a crime mystery novel some time ago. It's not what I started out writing nut why not step out of the comfort zone a bit. Right now I'm still planning it out and it's surprising how many characters seem to come out of the wood work. My problem is, every time I start writing down what is going to happen in a chapter I find myself doing the full write up. I'm sure that's not how it is meant to be, I'm just not used to planning to that degree. Still we push ahead and try to pull it all together.