adding a Convert.ToInt32 Method

{
     ABCDataContext context = GetDBContext();
     var item = (from e in Context.TPFStatus.AsEnumerable()
          where e.Document_Number == id
          select e.Document_Number).Single();
            return item;
     int value = 0;
     if(item is int)
         value = (int)item;
     else
         value = Convert.ToInt32(item.ToString());
}

Try this