DC published its milestone 1000th issue of Detective Comics on Wednesday and, on that same day, the publisher received a congratulatory note from an unexpected source.Marvel Comics Editor-in-Chief C.B. Cebulski congratulated DC on its landmark issue. On his Twitter page, Cebulski wrote, "Congratulations to everyone at DC Comics, and every creator who has ever worked on Batman, on the release of Detective Comics #1000 today! Such an amazing milestone to reach. Can't wait to read it!"RELATED: Kevin Smith, Jim Lee Reveal the Secret Origin of Batman's Bat-Symbol

The publishers' once-friendly rivalry has gotten testier in recent years, but that didn't stop Marvel's EiC from reaching out to its cross-country rival and acknowledging an achievement eight decades in the making. The move isn't likely to be reciprocated any time soon, though, but it's not because of the companies' frosty relations; Marvel is simply hundreds of issues away from reaching its first such accomplishment.

RELATED: Detective Comics #1000 is a Wonderful Celebration of Batman's Legacy

While Detective Comics is DC's oldest running title, it wasn't the first to reach its millennial milestone. DC published Action Comics #1000 last year. Action Comics overtook its older companion title thanks to a weekly publishing schedule for a several months during the late '80s.

Detective Comics #1000 features stories by Scott Snyder, Greg Capullo, Kevin Smith, Jim Lee, Paul Dini, Dustin Nguyen, Warren Ellis, Becky Cloonan, Denny O'Neil, Steve Epting, Christopher Priest, Neal Adams, Brian Michael Bendis, Alex Maleev, Geoff Johns, Kelley Jones, James Tynion IV, Alvaro Martinez-Bueno, Tom King, Tony S. Daniel, Joelle Jones, Peter J. Tomasi and Doug Mahnke.