as of january 1, 2006, the warner-amex units are separated from each other as a result of viacom dividing itself into two companies, "new" viacom and cbs corporation. showtime networks became a unit of cbs while the mtv networks became a unit of the new viacom. in december 2019, viacom and cbs corporation remerged into a single entity under the name viacomcbs, which reunited the two former warner-amex units.