"vary the world over" -> "vary across the world"

I think we should try to avoid idioms/phrases/colloquialisms where we can, to make the docs a little more accessible to those who don't speak English as a first language. We've never had any feedback on the issue, but I did previously remove many from the docs and try to keep the language as basic as possible. I'm not sure if "the world over" is a well know phrase outside North America? This is all totally up for debate though, I could be wrong.
Thoughts?