I'd like to see other angles on him (or her) but that's a juvenile or possibly mature male Latrodectus of some sort - in Idaho, either a Western Black Widow (Latrodectus hesperus) or possibly a Brown Widow (Latrodectus geometricus).
Definitely a male Latrodectus. Looks like a geometricus I found a couple years ago in my backyard except mine was a female. Latrodectus make some great pets. Not shy, not aggressive but the best eaters I've ever seen. Males, not so much. He's living on borrowed time