Giddeon has decided to follow and obey God. The first thing he is told to do is get rid of the "idols". God cannot act on Israel's behalf while they are still worshipping other Gods. On Israel's behalf, he obeys. He probably has told his father about about the visit of the Angel so his father is not surprised by his further action.
Sometimes, and this is one of those occasions, when we know we will be opposed and there is no benefit of putting ourselves in harms way. He went quietly into the night and did God's work and then sat back and waited for God to take care of the matter. His father met the challenge of dealing with the towns people and set forth the challenge to let Baal take care of himself. I see this as an action of faith as Gideon knew he was putting his life, and the life of his servants in danger. He let God take care of the situation.
I need to do more of that in my life! Have a great day, Joy