A320 flight crew experiences an engine stall at FL350 and retards the thrust lever to idle. An emergency is declared and the flight diverts to the nearest suitable airport with right engine at idle.

Narrative

During cruise at FL350 approximately 2 hours 45 minutes into flight; I heard a loud bang and felt the aircraft shudder. Looking down at the E/WD; I saw the ECAM 'Eng 2 Stall' and saw engine indications that back this up. I immediately retarded the power to idle on engine 2 and asked for the QRH. Retarding the power to idle stopped the stall and the ECAM disappeared. We declared an emergency and began the driftdown. ATC advised that ZZZ (about 80 NM southeast) was available and the weather was good. I continued to fly and took over communications with ATC. The Captain communicated with Dispatch; the flight attendants; and the passengers. We were vectored for a visual approach to ZZZ. We discussed leaving the #2 engine running at idle and did so; discussed overweight landing (we were almost at maximum landing weight - maybe 500 LBS over); etc. and completed the necessary checklists. I briefed single engine approach and go-around procedures. I continued to fly and made an uneventful landing with #2 at idle and #1 operating normally. The touchdown was smooth and I avoided braking until below 80 KTS to prevent any brake issues. The emergency equipment visually inspected our brakes and engine 2 and we taxied to the gate normally. I believe we handled this emergency by the book and with great CRM and airmanship. No human factors adversely affected this event.