Summary of Significant Accounting Policies - Liquidity - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Jul. 31, 2018
Debt Instrument [Line Items]
Income (loss) from continuing operations, net of tax, attributable to parent	$ (57,601,000)
Net cash used in operating activities	(49,649,000)	$ (41,182,000)
Accumulated deficit	1,846,391,000		$ 1,915,556,000
Cash, cash equivalents, restricted cash, and short-term investments	153,770,000
3.5% Convertible Notes Due 2023
Debt Instrument [Line Items]
Aggregate principal amount	$ 82,440,000			$ 200,000,000