Varies relative to who you are flying with at the time !
If its a new troop then fairly comprehensive but still bearing in mind that he/she can read and only salient points emphasised.
If its an old hand that you know and trust 'standard brief ILS runway XX - any questions' will suffice.
If your Company SOP'S define what consists a 'standard' brief for departure/emergencies/arrivals then don't go over the whole nine yards if you both are fully conversant (as you should be) with such briefs. Anything non-standard of course needs to be discussed.
So - keep it short, punchy and relevant !