Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Income Taxes [Line Items]
Liability for uncertain tax positions	$ 200		$ 200		$ 300
Deferred income taxes on undistributed earnings				$ (337)
Income tax expense (benefit)	$ 564	$ (4,149)	$ 1,343	$ (3,308)
Effective income tax rate	14.80%	(303.70%)	16.80%	(81.30%)
Zhongli [Member]
Income Taxes [Line Items]
Income tax expense (benefit)		$ (4,400)		$ (4,400)
Foreign Subsidiaries [Member]
Income Taxes [Line Items]
Deferred income taxes on undistributed earnings			$ (600)		$ (700)