Adam Clarke on 2 Kings 11:18

His altars and images brake they in pieces - It is probable that Athaliah had set up the worship of Baal in Judah, as Jezebel had done in Israel; or probably it had never been removed since the days of Solomon. It was no wonder that Jehoiada began his reform with this act, when we learn from 2Chr 24:7, that the sons of Athaliah, that wicked woman, had broken up the house of God; and also all the dedicated things of the house of the Lord did they bestow upon Baalim.