Idolatry is ANYTHING that is more important in your life than God...
People are extremely idolatrous...e.x. Hollywood, spouses, children, work, money, sports, etc. Ever said, "My god would never send people to Hell." Well you're right, your god doesn't exist! My point is that even our fallacious statements (known or unknown) are idolatrous and blasphemous (the 3rd C)...
A wonderful book to read is Idols of the Heart:
Amazon.com: Idols of the Heart: Learning to Long...