I hit a parked car and left a note for them to contact, Is this considered as hit and run?

I reverse from parking lot and accidently hit a parked car. I left a note with my contact and name, but did not report to police. I did report to my insurance. Will this consider hit and run and what will happen? Police called us back and tell us, this is hit and run. Will they arrest the driver; even we admitted this is our fault.