Details Component usable in ItemDetailsRenderer?

When you click on a row in a grid and have defined an ItemDetailsRenderer, then the row details emerge. In my case I want the row details to be a Details component, in other words only its header should emerge. It would take another click on the arrow in the Details component to finally reveal all of the content.

When I implemented this, I found that the Details component does not open downwards, but upwards. I would expect it pushes the next grid row down to make room for its content. But instead it pushes the previous grid row up and half of it vanishes completely, if it is the first grid row.

Is this a bug or am I using the Details component in a way it was not intended to be used? My code is straightforward:

grid.setItemDetailsRenderer(new ComponentRenderer<>(bean -> {
	MyContent content = new MyContent(bean);
	return new Details("Reveal me", content);