There are many levels to this, a game design "document" can consist of many different components. Inside, there would be an abstract overview of the game idea, the story, the main characters and interactions they have. But on the other hand, you may also dive into the more technical aspects, and then as gmx0 said, something that is targeted as being a resource requirement.
The issue you will have is that surface-level game design documents don't really provide the full context. Game ideas evolve over time, requirements change when you discuss things with your artist/programmers. The standard roles also vary depending on whether you are talking about an AAA game studio, or a small studio. The idea of a producer doesn't really exist in the Indie scene. There will be one or more people enacting multiple roles at the same time, in which case, you would be the one to sit in that position.
This question needs a little bit more depth as to what/how you plan to go about creating the game. If its kickstarter you are after, then the responsibility to work out how much needs to be spent is mostly on your own shoulders. People with experience may be able to give you some analysis, publishers could do this, but if you aren't at a position where you can do that, I don't really believe the role of a stand-alone producer exists for indie games, simply because it is often the job of the main game creator to do that. (Introducing more roles will often just dilute requirements further, which is why indie's tend to stick with relatively small teams of people).
Making assumptions about what you are doing, I would strongly recommend not creating a kickstarter purely based off of a game design document, you want to be able to have a playable prototype to show people. I will also say that 3D games + animation are very expensive to make. Animation is a hugely time consuming process, so unless you are the artist/animator, I would be cautious if this is your first commercial/funded project. The general truth is, in the indie scene, no one really knows how much things should cost. Its a large area of lacking experience, but unfortunately something you only learn from having experience on projects.
