Business and Basis of Presentation - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Subsidiary	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of subsidiaries | Subsidiary			2
Net income (loss)	$ 3,395	$ (37,424)	$ (13,538)	$ (47,511)
Net cash used in operating activities			4,688	$ 28,117
Cash and cash equivalents	90,896		90,896		$ 60,037
Marketable securities	$ 16,376		$ 16,376		$ 51,607