Updating Multiple Files Indesign cs6

Hi,

I've just started using Indesign (cs6) and

I have 50 files (20 pages each) that need updating

They are all the same design and have common elements that need updating.

My question is, can a Master Document be used over multiple files? 

i.e. Can I have all the files in a folder and have a way to UPDATE ALL with the new master I create?

Or would I open each file and somehow apply the Master that way (can a master be copied across from 1 file to another??)

Any ideas or solutions would be really appreciated.

Thanks