As far as I know, it is an ides group that replaces the aristocratic ideas when you're every republic type except for noble, dutch, and merchant.
first idea: available mercenaries 50%
second idea: Morale of armies 10%
third idea: national revolt risk -1.00
fourth idea: merchants +1
fifth idea: production efficiency 20%
sixth idea: tolerance of heathens +2
seventh idea: manpower recovery speed
final idea: technology cost -10%
It is a nice idea group that when stacked with other idea groups, you get a large advantage.
first idea: available mercenaries 50%
second idea: Morale of armies 10%
third idea: national revolt risk -1.00
fourth idea: merchants +1
fifth idea: production efficiency 20%
sixth idea: tolerance of heathens +2
seventh idea: manpower recovery speed
final idea: technology cost -10%
It is a nice idea group that when stacked with other idea groups, you get a large advantage.