Yes, my own denomination, the Lutheran Church-Missouri Synod, fully recognizes most other mainstream denominations as fellow Christians. This includes but is not limited to the Catholic, Orthodox and Protestant branches. I'm very proud of that, especially as that has always been my personal, private view as well 🙂
Naturally, I believe the doctrine of the LCMS is the truest, closest to the pure Christian faith as is possible this side of heaven. I'd be a hypocrite to believe that of another denomination, yet remain an LCMS member! But I accept as Christian any person or denomination which confesses and upholds the basic Christian doctrines summed up and expressed in the three great ecumenical Creeds of the Christian faith: the Apostles' Creed, the Nicene Creed and the Athanasian Creed. THESE are the core, non-negotiable beliefs one must believe and uphold, in order to be saved. This is the "demarcation line."