Information on market risk and fair value of financial assets and liabilities (excluding Orange Bank) - Book value of derivatives, net (Details) - Telecom activities, operating segment [member] - Operating segments [member] - EUR (€) € in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about financial instruments [line items]
Derivatives, net amount	€ 138	€ (460)	€ (729)
Derivatives [member]
Disclosure of detailed information about financial instruments [line items]
Derivatives, net amount	138		€ (729)
Level 2 of fair value hierarchy [member] | Derivatives [member]
Disclosure of detailed information about financial instruments [line items]
Derivatives, net amount	€ 138