Depends - if you actually mean dark idol ( the little rock monster thing ) , then no - that dungeon is pretty easy, other than you probably want a healer at low level because there is a lot of aoe.I need a dark idol thing to evo Logan, that's from the hard dungeon when it comes around right? I'm gonna get my shit pushed in when that comes around aren't I?
If you meant dark totem ( the bigger, pyramid shape guy ), then that's significantly harder, because they are random appearance in other totem dungeons, although there's a special dark totem dungeon up right now. Mid-max 4* team should be ok with totem dungeons, some benefit to having a mono color team ( you can make some ores and seals of your colors, makes it easier ). If your guys are 3* or low level 4* it could be tricky.