The integration between Aha and TFS is on the Feature. So first an Idea has to be promoted to Feature, and then the Feature pushed to TFS. When the item is updated in TFS that information flows back to the Feature in Aha, but it would be nice if the Idea is then updated with that information as well.
Currently, when feature statuses are updated (to shipped), Ideas statuses are also marked as Shipped. This allows you to tie the status between Ideas and Features.