Share-Based Compensation - Change in Number of BSPCE/OSA/RSU/BSA (Details)	9 Months Ended
	Sep. 30, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Beginning balance (in shares)	7,902,287
Granted (in shares)	2,009,928
Exercised (in shares)	(42,850)
Vested (in shares)	(1,130,171)
Forfeited (in shares)	(1,153,747)
Expired (in shares)	(3,600)
Ending balance (in shares)	7,581,847
OSA/BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	2,559,534
Granted, options (in shares)	140,513
Exercised, options (in shares)	(35,600)
Vested, options (in shares)
Forfeited, options (in shares)	(331,724)
Expired, options (in shares)	(3,600)
Ending balance, options (in shares)	2,329,123
RSU/PSU
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	4,978,986
Granted (in shares)	1,869,415
Exercised (in shares)	0
Vested (in shares)	(1,130,171)
Forfeited (in shares)	(809,281)
Expired (in shares)	0
Ending balance (in shares)	4,908,949
BSAs
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	363,767
Granted, options (in shares)	0
Exercised, options (in shares)	(7,250)
Vested, options (in shares)	0
Forfeited, options (in shares)	(12,742)
Expired, options (in shares)	0
Ending balance, options (in shares)	343,775