\renewcommand\@idxitem{\par\hangindent 20\p@}
\renewcommand\subitem{\@idxitem \hspace*{10\p@}}
\renewcommand\subsubitem{\@idxitem \hspace*{15\p@}}
\renewcommand\@idxitem{\par\hangindent 20\p@}
\renewcommand\subitem{\@idxitem \hspace*{10\p@}}
\renewcommand\subsubitem{\@idxitem \hspace*{15\p@}}