We have it on failfast, which enables all rules with their defaults.
We use the Gradle plugin, modifying Detekt to run after tests so it doesn't interfere with general development.
We use the IntelliJ Detekt plugin so we see warnings while developing.
All issues must be addressed in one way or another before pushing to CI server. Either fixing the code to address the issue, or deciding it's a 'false-positive', and Suppressing it.
Some rules are turned off for tests.
This way it's not possible to get a large backlog of issues that need to be addressed, and it's easy to see what types of things are being Suppressed by having it all in the code base.