each one = 3rd person singular - each one has his ideals
If this translates to "Each one has ITS ideals", how would you translate "each one has their ideals"? I would have thought it was the same in portuguese.
It's the same. I actually thought that was the suggested translation, because things usually don't have ideals. In any case, your translation works just as well.
In English it would have to be, "Each one has his/her ideals since the subject is "each one".