If you really, madly, deeply want to edit your docs, there's one way to do it -- click on the share button on the top right corner and choose "Open in Safari" to pull up the Google Drive webapp that's been available on iDevices since the service launched.
Google's webapp still lacks some of the functionality that its Android-based product features - such as indoor and 3D maps, and turn-by-turn directions - giving the firm an opportunity to promote devices powered by its own system over Apple's.