quantification? or emphasis?

[Paul Roochnik]

Dear Linguists,

What do you think of the following sentence:

"The managers arrived, all of them."

Now then, what about that final phrase, "all of them"?  Does it quantify 
"the managers"?  Does it emphasize the sentence?  Does it stand as some 
kind of apposition, or what?  I am trying to do an f-structure for this, 
and I am stuck.  Your thoughts, please.  Cheers from Paul.