Earnings Per Share - Anti-Dilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share (in shares)	4,324,027	1,308,667	3,282,625	928,159
Restricted share awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share (in shares)	4,183,514	1,305,872	3,212,368	894,012
Share options / BSPCE
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share (in shares)	140,513	2,795	70,257	34,147