Oh, yeah. My source code is like 60% comments by weight (or more). Although I typically produce separate standalone documentation for management or semi-technical staff. You know, people who know enough to possibly break something, but not enough to fix it afterward. I find it useful when trying to train new people too.

Also writing documentation in-code like JavaDoc or equivalents has always seemed great for me. Then you can have your toolchain generate the written documentation directly from that, and it can be updated easily based on what's actually documented in the code (but that does require that people keep that updated)