B737 First Officer reported a sudden loss in altitude of 500 feet during cruise while the aircraft was passing through turbulence. Captain recovered aircraft and flight continued with no injuries or damage reported.

Narrative

We were cruising at Flight Level 350 approaching waypoint ZZZZZ enroute to ZZZZ. I had just return to my seat after retrieving a crew meal and the Captain was coordinating with ZZZ Radio to deviate from course due to some weather that had popped up on the radar. He requested 5 miles left of course to traverse the weather at a gap that was both visually clear and clear on the radar return. ZZZ radio cleared us up to 10 miles left of course and the Captain selected another larger gap a little further left than the original 5-mile space selected. The Captain called the Flight Attendants and informed them that we were about to encounter some weather and to stop any service taking place and to take their seats for a few minutes. When we entered the weather there was some light chop and as we were about to exit; we hit some turbulence which caused an immediate loss of altitude of almost 500 feet. The autopilot kicked off and the Captain immediately took control of the aircraft; ensured the autopilot was off and reduced airspeed to .76M then recovered the aircraft to its original airspeed and altitude before reengaging the autopilot. The entire event was about 15-20 seconds in duration. What was weird was that the turbulence that caused the altitude deviation was not extreme or severe and was barely moderate. But it was like we hit a road bump then just dropped in altitude like in an elevator quickly and it was over. Following recovery; I heard the Flight Attendants checking in with each other in the back and while it caught everyone off guard no injuries or damages were reported. The rest of the flight continued normally. The Captain and I did some research to see how best to report the incident and what additional actions might be required and determined that we would each submit a report and that the Captain would submit an additional report for the altitude deviation.Cause: Weather event; possibly clear air turbulence associate with the weather we deviated for.Suggestions: Possibly making an even greater deviation for the weather?