Personally, I like it a lot better when the subroutine documentation is in the .cc file instead of the .h file.  Here's why:

-- For doxygen, it doesn't matter whether its in the .cc or the .h  (right?)
-- When fixing bugs, and doing maintenance, one spends almost all the time reading the code in the .cc file. It is inconvenient to have to also open a second file (the .h file) and read that too.  Its just nice to have everything in one place.
-- When trying to understand the API (the methods) provided by a class, its much nicer to have a small, compact list of methods one can quickly skim, instead of a big giant .h file that one has to carefully read. (e.g. to make sure one didn't accidentally skip over the one method you were hoping to find.)  Its a cognitive-overload thing: its just easier to read a short list of methods, than something that is 98% documentation and 2% method signatures.
-- I know that this is NOT the convention in commercial software, where they put docuementation in the .h files. But commercial software is not open source, you don't get the .cc file, and so of course they have to put it in the .h file. But that doesn't mean its better.

For this case, you don't have to change it back, we can leave it alone, I guess, but in the future, don't do this.