Ibiza's tiny airport was never built with transatlantic travelers in mind, which is precisely why the routing you choose matters more on this itinerary than almost any other in the Mediterranean. There's no nonstop option for business class from Detroit to Ibiza, so the real decision is which European gateway you funnel through: Lufthansa via Frankfurt or Munich, British Airways via London Heathrow, or Iberia via Madrid. Having flown all three combinations repeatedly, I'll say plainly that Iberia through Madrid is the connection built specifically for this route — Iberia operates the Madrid-Ibiza hop multiple times daily, and their A330 and A350 business class seats on the transatlantic leg offer a comfortable, fully flat product without the layover sprawl of a UK or German connection.
Lufthansa's newer Allegris business class, where available on select 787 and A350 rotations out of Frankfurt, is worth chasing if you don't mind a slightly longer connection — the suite doors and additional privacy make the second leg's short hop to Ibiza feel like a reward rather than an afterthought. British Airways' Club Suite, with its direct-aisle access and sliding door, is the strongest hard product of the three, but routing through Heathrow adds friction: Terminal 5 connections to short intra-European flights require real buffer time, and BA's Ibiza service is seasonal, concentrated in the warmer months. My insider tip: fly into Madrid a day early during peak summer weekends, since Ibiza-bound flights get fully booked with Spanish domestic travelers and even business class seats on the short hop can vanish fast — Iberia prioritizes elite status holders on that leg, so status matching before you go pays real dividends.
Shoulder season — April, May, September, and into October — is when this itinerary makes the most sense, both for lighter island crowds and for softer fares across all three carriers. Because pricing on this Detroit-Ibiza corridor shifts constantly depending on which hub is running promotions, setting up fare alerts is the smartest way to catch a premium cabin seat before it's gone.
