To the moon and the back.

It's also the last line of a popular children's book, "Guess How Much I Love You?"

A baby and parent bunny say how much they love each other, with increasing increments (the baby bunny's "this much," indicated by outstretched arms, is trumped by the parent bunny's "this much," also with outstretched arms that are longer). The final increment, spoken by the parent to the baby as he/she is asleep in the parent's arms, is "to the moon and back."

http://www.amazon.com/Guess-How-Much-Love-You/dp/076360013X

It conveys that the author loves his (wife and kid? kids? other family members?) very, very much.