Technically it's both IDW and DC. I guess DC holds the rights for all the characters but IDW has bought the license to reprint and distribute these Batman strips (in this type of format; hard cover).
It's always nice to get these old stories collected and reprinted in better quality and like G-Man said it makes for a great gift for your friends and loved ones. I'm definitely getting a copy for myself.
DC seems to be anti-old comics these days, they probably didn't foresee much of a profit from printing the strips themselves (getting originals, restoring and finding printers for the odd print size) and IDW probably offered them enough to forget about the hassle. IDW has been doing a fantastic job of restoring these old comics for a new audience, Dark Horse used to be the go to for restored comics but lately IDW, Hermes and Papercutz have been doing a better job of it.