Stock-based compensation - Stock Options and RSUs (Details)	3 Months Ended
	Mar. 31, 2021 shares
Stock Options
Number of Shares
Beginning Balance (in shares)	2,096,917
Granted (in shares)	0
Exercised/Converted (in shares)	(199,607)
Cancelled/Forfeited (in shares)	(59)
Ending Balance (in shares)	1,897,251
RSUs
Number of Units
Beginning Balance (in shares)	3,621,681
Granted (in shares)	6,950
Exercised/Converted (in shares)	(199,394)
Cancelled/Forfeited (in shares)	(63,888)
Ending Balance (in shares)	3,365,349