When you place a Detail marker with the 'left hand blob' you dont get anything in the detail window (although you could draw what you like later). If you use one of the other marker forms, rectangle or poly, you get an exploded view of the construction brought into the detail marker which you can then edit.
By the way, that annoying rectangle round your nice rounded marker style can be removed with Display Options - about half an hour of frustrated poking around in parameter tables and other places before i found that!!!.
