A Detail, in police jargon, is a very temporary assignment outside of your normal job description. Normally on a detail, we're tasked with providing a law enforcement presence at an event, or hired by a private concern to assist in a task where a law-enforcement presence is desired.
I've been a cop for thirty years and I've worked a lot of details. I'm a cop, a very good cop with long experience and a deep understanding of my job. I'm not "security". If you need security at an event, you're doing it all wrong, and there are private security companies that will provide contracts at great expense to provide "security" for your event. That ain't me. I am the Police. I know my job, and it isn't standing at a door making sure that everyone has a ticket. If you need ticket-takers, hire ticket-takers. That ain't me. If someone sneaks in and you want him arrested for trespassing, I'll do that, but I'm not your ticket-taker.
Some folks think that because I'm just standing quietly against a wall that I'm available for other tasks. Not so. Last night for example, several of my brethren were talking before the event. We were near a service area filled with folding chairs, discussing how best to handle the situations of the evening, when up walked this officious looking lady. "We need somebody to set up fifty chairs."
I reached over to the rack of chairs. "Let me help you." I said. I took a chair, unfolded it, and set it on the ground. "Do it just like that, fifty times."
She looked at me, stunned. "You mean that you're not going to help?"
"That's right, ma'am. I was sent here to provide a law enforcement presence. You're not paying me, so I don't work for you. If you want someone arrested, we'll be glad to help. If you want a disturbance quelled, we're the folks. We'll be polite and sociable, and we'll try to make sure everyone has a good time. But setting up chairs? Not likely."
She didn't speak to me the rest of the night. That's a good thing.