Cynara scolymus, the edible globe artichoke, is a native of the Mediterranean and introduced here as a food plant. Here are more photos and information from Plants for a Future. It is a type of thistle. There is also Cynara cardunculus (cardoon), its wild introduced relative. Here are more photos and information from Plants for a Future.
There are other thistles that occur in Idaho. The native ones in the genus Cirsium are:
There are four thistles that are classified as noxious weeds in Idaho. They are Cirsium arvense (Canada thistle), Carduus nutans (musk thistle), Onopordum acanthium (Scotch thistle), and Centaurea solstitialis (Yellow starthistle)—all are Eurasian imports.
Here are more photos and information on: Canada thistle from the National Park Service, Musk thistle from Plant Conservation Alliance's Alien Plant Working Group "Least Wanted". and Scotch thistle from Texas Invasives.
Perhaps your flower/weed is one of the native or introduced thistles. If you have photographs of it and don't recognize it in the ones I've suggested above, please visit our Plant Identification page to find links to several plant identification forums that accept photos of plants for identification.
Now, whether it is a wildflower or a weed is up to individual interpretation—one person's weed is another's wildflower!