Equity Method Investments and Other Investments - Summary of Equity Method Investments and Other Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Investment [Line Items]
Other Long-term Investments	$ 9,233	$ 11,628
DemeRx NB Inc [Member]
Investment [Line Items]
Other Long-term Investments	1,024	1,024
Juvenescence Limited [Member]
Investment [Line Items]
Other Long-term Investments	344	344
GABA Therapeutics Inc [Member]
Investment [Line Items]
Other Long-term Investments	$ 7,865	$ 10,260

Amount of long-term investments classified as other.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(f))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_OtherLongTermInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant