Go to "File->Settings (Preferences in OS X)->Editor->Code Style". At the bottom of the right pane there is a section for Editor Config options, which now includes an "Export" button. This will only export formatting options that are available in the Editor Config specification.

To include advanced options from IDEA you will have to save IntelliJ specific files with the project.
If you want to do this without saving the entire ".idea" folder and "*.iml" files, you can also export the IDEA configuration to an xml file and save in a place where everyone can get to it.
- In "File->Settings->Editor->Code Style". At the top of the right pane, there will be a "Scheme" field with an dropdown of options.
- Next to the dropdown is a cog/gear image that will expand to give some options depending on which scheme you have selected.
- The two options you need are the "Export..." option and the "Import Scheme" options which do what their names imply.
Go to "File->Settings (Preferences in OS X)->Editor->Code Style". At the bottom of the right pane there is a section for Editor Config options, which now includes an "Export" button. This will only export formatting options that are available in the Editor Config specification.

To include advanced options from IDEA you will have to save IntelliJ specific files with the project.
If you want to do this without saving the entire ".idea" folder and "*.iml" files, you can also export the IDEA configuration to an xml file and save in a place where everyone can get to it.
- In "File->Settings->Editor->Code Style". At the top of the right pane, there will be a "Scheme" field with an dropdown of options.
- Next to the dropdown is a cog/gear image that will expand to give some options depending on which scheme you have selected.
- The two options you need are the "Export..." option and the "Import Scheme" options which do what their names imply.
With later Intellijs (I'm using 2020.1), the configuration export is available via Settings -> Editor -> Code Style and then the gear icon. See the screenshot below, and the selected menu options:

Exporting code style settings from IntelliJ IDEA version 14.1.5 - Stack Overflow
IntelliJ Export Settings difference between Code Style and Code Style (schemes)? - Stack Overflow
java - Export Intellij IDEA code formatting rules to Eclipse - Stack Overflow
Formatting Code
If CheckStyle is an option for you, consider using it as 'single source of truth':
- create CheckStyle config
- install CheckStyle plugins in both Eclipse and IDEA
- import formatter configs from CheckStyle config
See answers to related question.
I haven't tried it yet.
At the moment there is no way to export IntelliJ code style to eclipse. You need to do it the other way around.
You can also check IntelliJ plugin called "Eclipse Code Formatter" (link), but it the same way, from Eclipse to IntelliJ.
I'm using IntelliJ 14.1.4