David Letterman says it's "too bad" Craig Ferguson is stepping down from "The Late Late Show."

Ferguson shared his plan to leave the CBS show at the end of the year on Monday, and on Tuesday's episode of the "Late Show," Letterman saluted the Scottish comedian who has followed him on TV for the past ten years. Dave congratulated Craig on a great run, and praised him for having a show unlike any other in late night. He said it's "virtually impossible" to be unique in the world of television, and wished Ferguson well in whatever he does next.

Letterman, meanwhile, is also leaving his late-night talk show. He's set to retire from the "Late Show" sometime next year, at which point Stephen Colbert will take over. So far there's no word on who will replace Ferguson on "The Late Late Show."