IdeaMux is a simple script that makes it easy to run TMux as a shell within the JetBrains IDE.
Using TMux has a few advantages over using another shell. Instead of hiding the shell, you can use the key combination for detaching the session and the windows opened within the TMux session will continue to exist. TMux also makes it easy to create new windows, split windows, and has a better scrollback buffer. You can get all of the benefits of TMux within the JetBrains IDE's shell.
To use the script, download the bash file and make it executable. Then go to Preferences > Tools > Terminal and set the shell path to the location of the script.