The first time my husband relapsed post rehab I enforced the boundary that I would not live with an active alcoholic so he needed to leave and move out. I told him that I was sorry that he drank again, I was sorry he was struggling with sobriety BUT that I needed to take care of myself and living with a person who is struggling makes life difficult for me. I want to and need to put myself and my children in a healthy environment and our home needs to be a safe place for us. I told him that I didn't care if he left or if we left but we would not live with or around active alcoholism. I also told him that I loved him very much and I was very sorry that he was struggling and that I wasn't mad that he relapsed, but naturally I was disappointed that it happened. I told him that I wanted him to be sober because he deserves to live a sober life and enjoy it. (I also happen to deserve a sober husband and our children deserve a sober dad.)
Hope that helps. And the last time he relapsed I didn't respond as nicely as that. Same idea but it was much shorter.
To me detaching means that the anger isn't there though. I was a much less effected by his relapse because I fully accepted that it wasn't about me or because of me and it really didn't effect much of MY day to day life. His drinking is 100% about him and he really is the only one who deals with the ramifications of it at this point in time.