Significant Events and Transactions of the Period - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Jul. 26, 2019	Feb. 08, 2019	Dec. 31, 2018	Oct. 25, 2018
Restructuring Cost and Reserve [Line Items]
Treasury stock (in shares)	4,533,650	3,903,673			3,500,000
Shares authorized to be repurchased and retired (in shares)				1,600,000
Closing R&D Operations In Palo Alto
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 449
New Organization Structure
Restructuring Cost and Reserve [Line Items]
Restructuring costs	772
American Depositary Shares
Restructuring Cost and Reserve [Line Items]
Authorized amount of share repurchase program			$ 80,000			$ 80,000
Treasury stock (in shares)		3,200,000
Research and Development expense | New Organization Structure
Restructuring Cost and Reserve [Line Items]
Restructuring costs	200
Sales and Operations expense | New Organization Structure
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 600