You can use import and export to copy styles between documents. The style is exported in a special *.styxml file, which is then imported into another Inventor document.
Sharing styles by importing and exporting is different from using a style library to share styles. Some guidelines to keep in mind when importing and exporting styles:
A style library maintains each style type in a separate .xml file.
If the exported style has substyles, such as a dimension style using the text style as a substyle, it is also exported in the same file.