I agree that it determining the amount of description needed in a piece of writing is partly a problem of finding the right balance to keep it readable and partly a matter of style. As inoue77 and lacygnette said, just having more description isn't the point: what you choose to describe and how is what makes all the difference.
Something I see often in writing is dialogue or even whole scenes that read more like a script than a novel. I think writers often forget that, in making the mental movie for a reader, you need to be everything: not just the screenwriter, but also the set designer, the costume designer, and most importantly the actors. I've found it really helps me to look at a dialogue the way an actor would look at a script. If I were playing this character, how would I move? What would I be looking at? If you consider what gestures and postures would be the most relevant to an actor, then you can get a better sense of how to flesh out your dialogue.
But I have the opposite problem: I could sit down and write out every small physical detail of every moment of the story and be happy as a clam. I don't know if it's because I'm a more physical person, but I really need to inhabit not just the minds of my characters, but their bodies as well. I have to go back in my edits and take out much of my description about what my POV character was smelling at the time, whether the temperature of the room was warm or chilly, how the seams of their shirt were a little too tight and pinched under the arms...