If you ever figure out any tricks to get others to change, I'd be interested - I run in to the same problem :)

Conversely, I do get a fair number of requests to change my own detail level: I tend to strongly encourage people to ask for elaboration as needed, so I do get a fair number of "requests for additional detail". And occasionally I'll have someone cut me off for having answered a question they didn't intend (i.e. "I meant, what color is it?"). I've found demonstrating positive/happy body language in these situations, and verbally reinforcing that I like this, has made people do that more often.