[UglyToad]

So full disclosure, I don't tend to write or read documentation that is external to the in-IDE documentation.

But why is documenting the types helpful? The IDE, and for Java/JVM there's a choice of multiple, will tell you. Why waste precious hours of life rewriting what is already documented in the type system?

Sure I'd document the why of something but the idea types should have any form of documentation external to an IDE that can parse the language just seems... redundant.

Whenever I hop over the fence to dynamic languages sure I have to read documentation and large amounts of it is rubbish that could just be inferred from source but that's why I don't hop over there often.

[digisign]

Docs are typically built from source on modern platforms. There's not reason to restrict type information to a particular set of tools when you are bothering to build documentation. Otherwise might as well save your time.

[pvorb]

I think it just depends on how many users your library expects. When there's a huge user base, proper documentation pays off.

[watwut]

Rather, how many users not using Eclipse or Idea you expect. And in the context of java, the answer is "few outliers".