Detachment doesn't mean that you stop loving someone. It simply means that you live independently of their actions and deny them control over your emotional state.
I used to have a very close relationship with my mother. She even home-schooled me. We did a lot of things together. However, she has a number of cult-like beliefs that I left behind when I went to college, among them the belief that interracial marriage is an abominable sin. When I asked my W (who is half-Korean) to marry me, I knew that I would no longer have a relationship with my mother, and we have spoken only once, briefly at my grandfather's funeral, in the last six years.
Have I stopped loving my mother? Not in the slightest. If she were to come to me and say, "I've recognized the error of my beliefs and I'd like to be part of your life," then I would welcome her love with open arms.
At the same time, my mother's rejection of me no longer has any emotional impact on me. I am occasionally sad for her that she doesn't know her granddaughter, but that's all.
That's detachment, and it was certainly easier for me to do with my mother than it is proving with my W, but that is the goal.
Here's a good page on detachment. Others have posted some good threads on the topic ... I'll try to find them.
