This one does work both ways. The price is not bad at all sub 5CPM if you route both ways via DTW. There are some downsides of this run. You are talking redeye either way and you are talking about a very hard to get redeye upgrade from SFO as it is almost always full. But, you can not fault the price. Here are the numbers:
6,450 MQMs at 4.8CPM
Bookable on Delta.com
Be sure to use switch DL+ X:DTW if you are searching via ITA Matrix for other months.