What is the waiting period ('iddah) of a woman whose husband grants her khul' after a long period of separation?

Khulʿ (divorce at the wife's instance) necessitates separation between the spouses, and through it, the woman gains control over her affairs. The waiting period (ʿiddah) for a woman who has undergone khulʿ is, according to the majority of scholars, the same as that of a divorced woman, meaning three menstrual cycles. This is based on the Almighty's saying: "And divorced women shall wait concerning themselves for three menstrual periods" (Quran 2:228), and because khulʿ is a separation between the spouses during their lifetime after consummation, thus the waiting period is three menstrual cycles, similar to other forms of divorce.