The Detective Conan Anime started in 1996, and as of the time of this writing, is still going strong with 1,156 episodes to date.  

In 2004, Funimation began dubbing the show in English, but without video streaming serviced like we have today, it was difficult for its potential audience to have even knew it existed at the time.   The first 50 episoded aired at 12:30am and later at 1:00am on adult swim, the remaining episodes were only available on dvd.  After the 123rd episode, Funimation stopped dubbing the show😱😭.  

Jump ahead to 2022, and Bang Zoom! Entertainment started dubbing the most recent Detective Conan movies, and later the tv series finally got some more episodes dubbed in english.  Starting from episode 965 thru 1014.  So episodes 124 to episode 964 do not have an english dub.  I much prefer the old funimation cast to the new one, but just getting a new dub is a plus regardless.

The show is a modern masterpiece of the mystery genre, and is HUGE in Japan.   I think if they kept airing it here its audience would have eventually found it and it would have been a huge hit.  Look at the Dragon ball franchise.  It was first released it in America in 1989, but due to low ratings, it was canceled.  So they figured it just wasn't a show for American audiences.  But years later it was released again and this time, it's audience found it and it was a huge hit.  I think the same could have happened with Det Conan, it deserves a complete english dub.