Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	May 01, 2020	Dec. 31, 2019	Dec. 19, 2019
Disclosure Of Lease [Line Items]
Operating right of use assets	$ 7,357				$ 7,357			$ 6,934
Operating lease liability	7,340				7,340			$ 7,300
Fair value of annual lease payments	$ 9,881				$ 9,881
Weighted-average remaining lease term	13 years 9 months 18 days			6 years 7 months 6 days	13 years 9 months 18 days	6 years 7 months 6 days
Average discount rate	4.40%			7.50%	4.40%	7.50%
Impairment loss related to the right of use asset					$ 6,220	$ 0
Annual interest rate									10.00%
Gain on settlement of operating lease liabilities					5,706	0
Cash payment for leases	$ 115			$ 448	961	$ 968
Real Estate
Disclosure Of Lease [Line Items]
Operating lease liability	5,800				5,800
Impairment loss related to the right of use asset		$ 5,300	$ 900
Remaining operating lease liability	6,400				6,400
Gain on settlement of operating lease liabilities	4,900	800
Cash payment for leases	1,500
Real Estate | Accounts payable
Disclosure Of Lease [Line Items]
Operating lease liability	$ 600				$ 600
China
Disclosure Of Lease [Line Items]
Operating right of use assets							$ 7,200
Operating lease liability							7,200
Fair value of annual lease payments							$ 700
Promissory Note
Disclosure Of Lease [Line Items]
Operating lease liability		100
Remaining operating lease liability		$ 900
Annual interest rate		4.00%