Wiktionary
adv. (context idiomatic English) Covering a complete range; comprehensively; from beginning to end.(R:OCD2: page=1)(R:MW3 1976: page=1)
Wikipedia
From A to Z is a musical revue with a book by Woody Allen, Herbert Farjeon, and Nina Warner Hook and songs by Jerry Herman, Fred Ebb, Mary Rodgers, Everett Sloane, Jay Thompson, Dickson Hughes, Jack Holmes, Paul Klein, Norman Martin, William Dyer, and Charles Zwar.
Usage examples of "from a to z".
The names ran from A to Z, and there were about five hundred of them.
A possible route for him is indicated by the dotted line from A to Z.
It's a case of the survival of the fittest, and you've got to understand that the air over the Lines is swarming with men who know the game from A to Z.
He'd got Felix hands down for the killings and the snatch, got what he needed from A to Z.
He would redeem this city: Geographers' London, all the way from A to Z.
But by every Hagion from A to Z, I'd like to know what is going on!
Time can tick from A to Z in one universe and from Z to A in another, but only an observer outside both universes is going to know that, so long as within each universe the daily flow runs from cause to effect and not the other way.