getRID returning negative number

Is this normal?! I cannot use a negative number to find the data so how do I get the real number?

here is my code:

catalog = app.intranet.portal_catalog._catalog
all_news_items = catalog.searchResults({'portal_type': 'News Item'})
for news in all_news_items:
 print("Title: " + news['Title'] + " ,RID: " + news.getRID())
#returns: Title: Hello ,RID: -190202187

I don't care if it is negative or not but when I want to use getIndexDataForRID(rid) then it throws errors since it is negative!