Organization and Operations - Stock Purchase Agreement and Series X Preferred Stock (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) shares	Jan. 28, 2021	Dec. 31, 2020 shares
Stock Purchase Agreement and Series X Preferred Stock
Net proceeds from issuance of private placement | $	$ 104,261
Number of shares of common stock into which each share of Series X Preferred Stock may be converted	166.67
Preferred stock, outstanding (in shares)	0		0
Minimum
Stock Purchase Agreement and Series X Preferred Stock
Common stock, percentage of beneficial ownership initially, after conversion	4.99%
Common stock, percentage of beneficial ownership thereafter, after conversion	4.99%
Maximum
Stock Purchase Agreement and Series X Preferred Stock
Common stock, percentage of beneficial ownership initially, after conversion	9.99%
Common stock, percentage of beneficial ownership thereafter, after conversion	19.99%
Series X redeemable convertible preferred stock
Stock Purchase Agreement and Series X Preferred Stock
Series X Preferred Stock at Transaction Date	88,882
Number of shares of common stock into which each share of Series X Preferred Stock may be converted	166.67
Number of Series X preferred shares converted during period	54,622
Number of common shares issued from conversion of Series X preferred shares	9,103,664
Number of common shares issuable upon conversion of preferred stock (in shares)	5,242,501
Preferred stock, outstanding (in shares)	31,455		0
Series X redeemable convertible preferred stock | Shares issued in merger
Stock Purchase Agreement and Series X Preferred Stock
Series X redeemable convertible preferred stock, shares issued	50,504
Series X redeemable convertible preferred stock | Shares issued in February 2021 Financing
Stock Purchase Agreement and Series X Preferred Stock
Series X redeemable convertible preferred stock, shares issued	35,573
Series X redeemable convertible preferred stock | Warrants assumed in merger
Stock Purchase Agreement and Series X Preferred Stock
Series X Preferred Stock at Transaction Date	2,805
Series X redeemable convertible preferred stock | Quellis Biosciences, Inc
Stock Purchase Agreement and Series X Preferred Stock
Number of shares of common stock into which each share of Series X Preferred Stock may be converted		166.67
Series X redeemable convertible preferred stock | Quellis Biosciences, Inc | Stock Purchase Agreement
Stock Purchase Agreement and Series X Preferred Stock
Issuance of preferred stock in a private offering of public equity, net of issuance costs (in shares)	35,573
Gross proceeds from issuance of preferred stock in a private offering | $	$ 110,000
Net proceeds from issuance of private placement | $	104,300
Beneficial conversion feature | $	19,600
Issuance costs | $	$ 5,700
Number of shares of common stock into which each share of Series X Preferred Stock may be converted	166.67