Convertible Notes - Summary of the carrying value of the convertible notes (Detail) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount		$ 175,000	$ 175,000
Plus: premium on Additional Notes		250	250
Carrying amount		175,250	175,250
Less: Unamortized discount (1)	[1]		(4,207)
Less: Unamortized issuance costs(1)	[1]	(4,087)	(4,397)
Carrying amount		$ 171,163	$ 166,646
Effective interest rate(2)	[2]	5.30%	6.29%

[1] Unamortized discount reduced by $4,207 and unamortized issuance costs increased by $119 upon the early adoption of ASU 2020-06, Debt – Debt with Conversion and Other Options, on January 1, 2021. The discount previously arose from the bifurcation of the conversion option which occurred prior to the adoption of ASU 2020-06. The unamortized issuance costs are reported net of the unamortized premium on the Additional Notes.

[2] Includes amortization of the issuance costs allocated to the Convertible Notes and amortization of the premium associated with the Additional Notes. The effective interest rate prior to January 1, 2021 also included amortization of the discount arising from the bifurcation of the conversion option.