Two iPhones sharing the same Apple ID,is it possible to move one to a new Apple ID without losing the data?

My husband and I have used the same Apple ID for years – but lately some of the iOS updates mean that we are getting each other's calls and the call log now shows all our joint calls – it's becoming increasingly difficult to work out whose calls are for who – is it possible to set my husband up with a new Apple ID and transfer the phone data and cloud data across to the new ID without losing messages, contacts – photos etc. How would I do this?