Acquisitions - Schedule of Estimated Fair Values of Assets Acquired and Liabilities Assumed (Detail)2 - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Oct. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 0	$ 80,131		$ 71,368
Medical Surgery Technologies Limited
Business Acquisition [Line Items]
Property and equipment			$ 43
In-process research and development			10,633
Goodwill	$ 9,600		9,638
Net assets acquired			$ 20,314