Andy Leonard has written this beautiful SSIS Package that you can use to loop through your SQL Server instances, then loop through each database in a SQL Server instance, and finally generate meta data ( columns names, datatypes) documentation for the database objects like tables and views in each database.
Very simple and neat implementation. Link to download the package is at the bottom of the article. The package is free to download, but forces you to register for free on the download DNN site.