Manage cache should open up the cache directory, in windows it defaults to C:\Users\<username>\AppData\Local\Arelle\cache
you can set the environment variable "XDG_CONFIG_HOME", this will set the directory 2 levels above the cache, if you use the environment variable to change the config home path, you might want to copy the existing "C:\Users\<username>\AppData\Local\Arelle" to the new location to keep your existing settings and cache.