For a customer we need to generate detailed test reports for integration tests which not only show, that everything is green, but also what the test did. My colleagues and I
Maybe it is worth taking a look on "executable specification" / BDD tools like FIT/FitNesse, Concordion, Cucumber, JBehave etc.
With this practice you will have a possibility not only satisfy the customer's requirement formally, but you will be able do bring transparency onto a new level.
Shortly speaking, all these tools allow you (or, better, customer) to define scenarios using natural language or tables, define binding of natural language constructs to real code, and run these scenarios and see if they succeed or fail. Actually you will have a "live" spec which shows what is already working as expected and what is not.
See a good discussion on these tools: What are the differences between BDD frameworks for Java?