There's no built-in shortcut, but you can do the following:

Using the keyboard, select the item for which you want detail

(You could record a macro, and assign a keyboard shortcut, to make the
following steps easier to repeat later.)

Press the F10 key, to activate the menu bars
Press Ctrl + Tab until the PivotTable menu bar is activated
Use the arrow keys to move to the Show Detail button
Press the Enter key


wrote:
I have been unable to find a keyboard shortcut in Excel for drilling-down in
a PivotTable. I am trying to address accessibility issues, and I believe this
is the last one I have. I have checked the on-line help and the Website. Any
help will be most appreciated.


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html