Fair Value Measurements - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	May 05, 2020	Nov. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value assets, Level 1 to Level 2 transfers amount			$ 0		$ 0
Fair value assets, Level 2 to Level 1 transfers amount			0		0
Fair value assets, Level 1 to Level 3 transfers amount			0		0
Fair value assets, Level 2 To Level 3 transfers amount			0		0
Fair value assets, Level 3 to Level 2 transfers amount			0		0
Fair value assets, Level 3 To Level 1 transfers amount			0		0
TSG
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Agreement period		20 years
Number of common shares received under agreement (in shares)	0.2253	1,100,000
Additional value of common shares receivable under agreement upon exercise of first option by TSG		$ 5,000,000.0
Common shares, sales restriction period, upon exercise of first option		1 year
Cumulative unrealized gains (losses)			6,500,000	$ 100,000	3,100,000	$ 1,500,000
TSG | Marketable Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, total			15,800,000		15,800,000		$ 14,000,000.0
Cumulative unrealized gains (losses)					5,500,000		$ 3,700,000
TSG | Restricted Cash and Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, total			$ 6,000,000.0		6,000,000.0
Cumulative unrealized gains (losses)					$ 1,300,000