Design Decisions Document - What is too much?

My first draft of the design decisions document is already over six pages and I haven't finished saying everything I want to say. I know I need to rewrite it to tidy it up. There's alot on pros, cons, and alternatives.
Did anyone feel that they were hurt by having too much information in this document? Is it OK to cover minor design decisions as well as major ones? What is a typical length for this document?
Thanks in advance,
Robin

I think it sounds fine. Mine was 5 pages. So to me 7 isn't too much, and as you said you will probably edit some of it out.
Mark