Intellij IDEA with ideavim. Cannot copy text from another source

Solution 1:

Vim's yank command doesn't yank to the system clipboard by default; it yanks to the unnamed register. You can use the * or + register to access the system clipboard; also see this wiki article for more information. Or just set this option in your ~/.ideavimrc:

set clipboard+=unnamed

This ~/.ideavimrc setting has been supported in IdeaVim since VIM-476 was implemented in version 0.38. If the file does not exist create it in your user/home directory.

Note also that this is all standard Vim behavior; none of it is specific to IdeaVim except for the name of the config file.