How do I know if I'm not diving deep enough into my world and characters?

Let me try to add some more details. As most of you have probably guessed, it takes everything in me to write in detail. I want to be a writer so I've been fighting the urge to be vague. I'm also tired, so I find details more difficult to produce at this moment. Anyway on to the question.

I'm working on a world. Well, a hidden world within ours. It's a hidden world of dragons who have built their own society and created a system with rules and guidelines upon which they live and thrive. I've been able to create some information like some rules, occupations, politics, biology, law, etc. but I'm trying to figure out whether or not I need to dive deeper. Scratch that, I know I need to dive in deeper, but I don't know how much deeper. How does a person know they've created enough information about their worlds? How does a person know that they've dived deep enough into their world? The same goes for characters. I find characters a little easier because when I dive into them, their voice begins popping up everywhere and they show me how they respond in different situations.

Feel free to ask details. If you, however, need details on the story in order to answer let me know and I'll send you a PM. I don't want to post my stories details all over the forum.

How do I know if I'm not diving deep enough into my world and characters?