0001109357 2020-12-08 2020-12-08 0001109357 exc:ExelonGenerationCoLLCMember 2020-12-08 2020-12-08 PA 10 South Dearborn Street P.O. Box 805379 Chicago IL 60680-5379 (800) 483-3220 PA 300 Exelon Way Kennett Square PA 19348-2473 (610) 765-5959 false 0001109357 0001168165 false 8-K 2020-12-08 001-16169 EXELON CORPORATION 23-2990190 PA 10 South Dearborn Street P.O. Box 805379 Chicago IL 60680-5379 (800) 483-3220 333-85496 EXELON GENERATION COMPANY, LLC 23-3064219 PA 300 Exelon Way Kennett Square PA 19348-2473 (610) 765-5959 false false false false Common Stock, without par value EXC NASDAQ false