Fair Value Measurements - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Fair Value Measurements Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 97,929,000	$ 95,260,000
Liabilities measured at fair value	0	0
Fair Value Measurements Recurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 0	$ 0
2019 Convertible Senior Notes due 2026
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt instrument, maturity year	2026