Converting fonts back to fonts?

Have a one page PDF do***ent containing just a small amount of text -- 
but file size is 900 kB instead of say 20 or 30 kB.

Opening it in Illustrator and selecting any one character in the text 
causes the Type palette to indicate that each such character is 
Helvetica Neue, Regular, 14 pt -- but looking more closely at the 
character itself seems to show that each character in the text has been, 
for some reason, converted into a separate and complex vector object.

And, pulling down the Type >> Find Fonts menu command seems to show that 
the do***ent contains _no_ fonts at all (in either half of the Find 
window) . . . ???

Is there a quick, safe way to convert this do***ent back into "real 
type"?