Cash, Cash Equivalents and Short-Term Investments - Additional Information (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Cash, Cash Equivalents and Short-Term Investments
Gains (losses) on available-for-sale investments	$ (6,900)	$ 10,000
Equity Securities, FV-NI	$ 14,500,000	$ 14,500,000

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

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