Yes, definitely! I've always received high praise by my colleagues and managers from my documentation. I do it for the people who have to inherit my work should I win the lottery, get a massive inheritance from a long-lost relative, or more realistically, move on to better pastures.
I've been in situations where my predecessors or my colleagues have left the company for better pastures, and I inherited their work. In situations where there was virtually NO documentation on the code, I have wasted HOURS of time trying to interpret what the person was trying to do and why the person was doing what s/he was doing. I understand that developers, in general, hate documentation. However, Java and .NET have very simple commenting standards used by tools that can generate documentation (javadoc, Sandcastle) that hardly take any more time to write.