If they are airline employees and not cops I'm not aware of any way they can detain you, short of a citizen's arrest which usually requires them to have observe

If they are airline employees and not cops I'm not aware of any way they can detain you, short of a citizen's arrest which usually requires them to have observed you committing a felony? In this case I would just declare that I'm leaving and if any resistance, demand the real cops be called or call them yourself. Same if they refuse to return your cash and/or luggage.