CRJ 700 First Officer reported failure of the #2 generator at cruise and flight crew elected to start the APU; restoring electrical power; and continued to destination airport.

Narrative

I heard a pop; like circuit breaker; followed by a loss of cockpit integrated lights then a Hydraulic Pump 3A amber message and RWSHLD HEAT R amber message. The Captain transferred radios to me and began assessing QRH procedures. We discussed the messages and reviewed the Electrics Synoptics Page. The Synoptic Page indicated a Gen 2 failure and Bus 2 unpowered. We decided to run Gen 2 Off procedure first as the additional amber messages and status messages were related to loss of Bus 2. We reset Gen 2 per procedure. The Integrated Drive Generator came back online but the Gen did not with Gen 2 message persisting. Procedure called for APU start. We were at FL380. We notified ATC of the situation and requested a lower altitude to start the APU. We received FL320. I turned on the seat belt sign and started the descent. After passing through FL370 we started the APU and power was restored to Bus 2. We then proceeded to address the QRH for the additional amber messages and reset the R Window Heat and confirmed Hydraulic Pump 3A was powered. After APU start we received an APU Fault status message but the APU continued to function for the remainder of the flight. We notified maintenance and dispatch. The flight terminated ZZZ without further incident. When the system failure occurred we were on the ZZZZZ arrival into ZZZ instructed to maintain 300 until ZZZZZ then published speeds after ZZZZZ. I began slowing the aircraft late and crossed ZZZZZ at about 270. ATC instructed us to slow to 250 and resume published speeds. I complied and we continued the arrival.