How long does it typically take for editor's final decision after reviews are completed?
Reviewers can only recommend a verdict so what they say is not necessarily the outcome, the editor has final say. Of course if two reviews agree then it is very likely the outcome will be what they suggest. In a normal review situation involving an editor, the reviewers provide their reviews to the editor who in turn will make a judgement and pass on comments and possible suggestions for improvements to you. If your manuscript is in an open review system (such as the discussion format of Copernicus Open Access journals), you  may see the reviews before final decisions are taken and in such a case, I would not trust reviewers opinions on the verdict until you also hear so from the editor.

As is pointed out in a comment, it is a bit intriguing that you seem to have the reviewers comments but not that from the editor. The time between completion of reviews and to a decision by an editor will vary depending on many factors. The editor has to read the reviews in light of the manuscript and then value the comments and provide a synthesis of the outcome for you. Obviously the editor will have other manuscripts to handle in parallel which influences the time a decision may take. To state a time that can be applied to any situation or journal is therefore pointless. I am, however, certain that any serious editor is not keen to hold on to a decision for any extended period. With the journals I have published and the one where I am Editor-in-Chief times from receipt of reviews to decision can vary from maybe days up to a month in rare cases. This seems reasonable for the field in which I work but I am sure that such times vary between both field and journals within a field.