CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at the beginning of the period at Dec. 31, 2020	$ 18	$ 829,424	$ (34)	$ (517,473)	$ 311,935
Balance at the beginning of the period (in shares) at Dec. 31, 2020	68,215,022
Changes in equity
Issuance of Class A shares under incentive award plans and employee share purchase plan		1,106			1,106
Issuance of Class A shares under incentive award plans and employee share purchase plan (in shares)	115,012
Share-based compensation expense		7,126			7,126
Unrealized gain on short-term investments and currency translation adjustments			13		13
Net loss				(49,484)	(49,484)
Balance at the end of the period at Mar. 31, 2021	$ 18	837,656	(21)	(566,957)	270,696
Balance at the end of the period (in shares) at Mar. 31, 2021	68,330,034
Balance at the beginning of the period at Dec. 31, 2020	$ 18	829,424	(34)	(517,473)	311,935
Balance at the beginning of the period (in shares) at Dec. 31, 2020	68,215,022
Changes in equity
Unrealized gain on short-term investments and currency translation adjustments					61
Net loss					(91,047)
Balance at the end of the period at Jun. 30, 2021	$ 18	844,260	27	(608,520)	235,785
Balance at the end of the period (in shares) at Jun. 30, 2021	68,464,749
Balance at the beginning of the period at Mar. 31, 2021	$ 18	837,656	(21)	(566,957)	270,696
Balance at the beginning of the period (in shares) at Mar. 31, 2021	68,330,034
Changes in equity
Issuance of Class A shares under incentive award plans and employee share purchase plan		887			887
Issuance of Class A shares under incentive award plans and employee share purchase plan (in shares)	134,715
Share-based compensation expense		5,717			5,717
Unrealized gain on short-term investments and currency translation adjustments			48		48
Net loss				(41,563)	(41,563)
Balance at the end of the period at Jun. 30, 2021	$ 18	844,260	27	(608,520)	235,785
Balance at the end of the period (in shares) at Jun. 30, 2021	68,464,749
Balance at the beginning of the period at Dec. 31, 2021	$ 18	860,482	(66)	(675,397)	185,037
Balance at the beginning of the period (in shares) at Dec. 31, 2021	69,060,403
Changes in equity
Issuance of Class A shares under incentive award plans and employee share purchase plan	$ 1	422			423
Issuance of Class A shares under incentive award plans and employee share purchase plan (in shares)	210,720
Share-based compensation expense		6,031			6,031
Unrealized gain on short-term investments and currency translation adjustments			(37)		(37)
Net loss				(25,210)	(25,210)
Balance at the end of the period at Mar. 31, 2022	$ 19	866,935	(103)	(700,607)	166,244
Balance at the end of the period (in shares) at Mar. 31, 2022	69,271,123
Balance at the beginning of the period at Dec. 31, 2021	$ 18	860,482	(66)	(675,397)	185,037
Balance at the beginning of the period (in shares) at Dec. 31, 2021	69,060,403
Changes in equity
Unrealized gain on short-term investments and currency translation adjustments					(24)
Net loss					(45,191)
Balance at the end of the period at Jun. 30, 2022	$ 19	874,153	(90)	(720,588)	153,494
Balance at the end of the period (in shares) at Jun. 30, 2022	69,426,767
Balance at the beginning of the period at Mar. 31, 2022	$ 19	866,935	(103)	(700,607)	166,244
Balance at the beginning of the period (in shares) at Mar. 31, 2022	69,271,123
Changes in equity
Issuance of Class A shares under incentive award plans and employee share purchase plan		542			542
Issuance of Class A shares under incentive award plans and employee share purchase plan (in shares)	155,644
Share-based compensation expense		6,676			6,676
Unrealized gain on short-term investments and currency translation adjustments			13		13
Net loss				(19,981)	(19,981)
Balance at the end of the period at Jun. 30, 2022	$ 19	$ 874,153	$ (90)	$ (720,588)	$ 153,494
Balance at the end of the period (in shares) at Jun. 30, 2022	69,426,767