ERD Generator for Dynamics CRM 2011/2013 is a Windows Form application that is can be used for Dynamics CRM 2011 or Dynamics CRM 2013.
This tool allows you to build ERD (Entity relationship diagrams) that are dynamically updated based on the published CRM entities and Fields. You can pick a source entity and build ERD around it. It generate a VISIO output but also lets you pick CSV to document Entity relationships.
It generates a CSV having details like:
It generates ERD in VISIO:
Hope it helps!