The IntelliTidy plugin for IntelliJ provides a single action for closing all documents and collapsing all trees.
Download it here.
If you are like me and have the desire like to clean up after a coding session by closing all of your windows and collapsing all of the trees, this plugin is for you. It will collapse every tree in every sidebar, including Git, Maven, Gradle, Project View, etc.
The IntelliTidy plugin for IntelliJ adds actions to the View menu, and also adds a <shift>-F11 keyboard shortcut.