Found $120 - Literally

Walking into the grocery store with my wife, I spotted a $20 bill in the middle of the parking lot. Looking around, I managed to find a total of $120. Had I seen someone drop it, I certainly would have returned it to them. Had it been "property" like a watch, I would have returned it to the store in case the owner came back looking for it.

Should I have taken the money into the store?