Financial Instruments - Schedule of Changes in Fair Value of Liability Classified Stock Options (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Derivative Liability Roll Forward [Roll Forward]
Liability at beginning of the period		$ 45,569
Liability at end of the period	$ 34,621	34,621
Liability classified stock options
Derivative Liability Roll Forward [Roll Forward]
Liability at beginning of the period	33,899	45,569
Reclassification to liabilities from equity	0	110
Increase (decrease) in fair value of liability classified stock options	(419)	(7,736)
Exercise of options	(209)	(775)
Unrealized foreign currency loss (gain)	1,350	(2,547)
Liability at end of the period	$ 34,621	$ 34,621