Detaching affects only cards that are currently Attached to another card. 1. Game effects that instruct a player to Detach a card that is currently not Attached to anything will do nothing.
§ 435.1.a Core Rules PDF (officieel)
§ 435 Detach
§ 435.1 Detaching is the act of unlinking two cards that are currently linked through the act of Attaching. This causes one to cease being Attached, and potentially causes the other to cease being a Top-Most card.
