Transcripts of corporate earnings calls are published by CQ FD Disclosure and go back to 2002. You can find them using this syntax:
rst=fndw and hd=Ford and hd=earnings
rst is the publication code and Ford is my example company. hd indicates search in the headline. I include earnings as there are other corporate events in CQ FD Disclosure. Factiva doesn't include tickers in its index, so you must use either the headline search or the company look up to limit by company.