B737-700
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 190
Aircraft Equipment Problem Critical
Flight Crew Landed As Precaution; Flight Crew Diverted
Aircraft
Operating with MEL due to #2 IDG (Integrated Drive Generator) Inoperative. MEL requires APU generator in lieu of offline generator. APU generator kicked offline.  Ran QRH; reset per QRH; then it kicked offline again within a minute. QRH says to land at nearest suitable airport. Diverted to ZZZ; which was roughly 180 miles away. Remainder of flight uneventful.
Our #2 IDG (Integrated Drive generator) was MEL'd and we were using the APU to power #2 Transfer BUS per the MEL. In cruise; the B Autopilot disconnected; and we got a #2 'source off' light. The APU GEN OFF BUS light was illuminated but the APU voltage and frequency read zero. We accomplished the 'Source Off' QRH. We were unable to get the APU back on the #2 BUS. Per QRH guidance; we diverted to ZZZ; the nearest suitable airport.Recommend dispatching aircraft with fewer MELs when transiting maintenance bases.
B737-700 flight crew reported diversion due to APU generator failure inflight following dispatch with on operating IDG.