Stock award plan - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended
	Jun. 08, 2022	Dec. 31, 2022	Dec. 31, 2020	Jun. 30, 2016	Mar. 31, 2024	Mar. 31, 2023	Apr. 30, 2022	Jun. 30, 2021	May 31, 2021	Jan. 31, 2020
Stock option plan
Share-based compensation expense					$ 18,378	$ 28,815
Unrecognized compensation cost					$ 156,300
Weighted average remaining service period for recognition of unrecognized compensation cost					2 years 4 months 24 days
Stock option
Stock option plan
Granted (in shares)					855,385
Options forfeited (in shares)					815,707
Expected dividend yield (as a percent)					0.00%
Weighted average grant date fair value (in dollars per share)					$ 13.49
Restricted stock units
Stock option plan
Granted (in shares)					1,785,660
Employee Stock Purchase Plan
Stock option plan
Number of shares authorized (in shares)								2,000,000	1,000,000
Award requisite service period				6 months
Purchase price of common stock, percent				85.00%
Employee stock purchase plan, voting percentage limit				5.00%
Share-based compensation expense					$ 600
1998 Employee, Director, and Consultant Stock Option Plan, 2009 Equity and Long-term Incentive Plan, and 2013 Stock Incentive Plan | Common stock
Stock option plan
Number of shares available for issuance					0
Amended 2013 LTIP
Stock option plan
Number of shares available for issuance					6,618,698
Number of additional shares authorized (in shares)	8,475,000
Amended 2013 LTIP | Maximum
Stock option plan
Number of shares authorized (in shares)	16,724,212
2020 Inducement Stock Incentive Plan | Common stock
Stock option plan
Number of shares available for issuance					1,989,827
Number of additional shares authorized (in shares)		1,700,000	1,000,000
2020 Inducement Stock Incentive Plan | Common stock | Maximum
Stock option plan
Number of shares authorized (in shares)							1,300,000			1,000,000
2020 Inducement Stock Incentive Plan | Stock option
Stock option plan
Granted (in shares)					855,385
Stockholder's specified ownership percentage					10.00%
Inducement grants for non-statutory stock options (in shares)					1,840
Vesting period					4 years
2020 Inducement Stock Incentive Plan | Stock option | Minimum
Stock option plan
Stock options granted, exercise price as percentage of the fair market value of common stock at grant date					100.00%
2020 Inducement Stock Incentive Plan | Stock option | Maximum
Stock option plan
Stock options granted to stockholder with specified ownership percentage, exercise price as percentage of the fair market value of common stock at grant date					110.00%
Expiration period					10 years
2020 Inducement Stock Incentive Plan | Restricted stock units
Stock option plan
Granted (in shares)					4,275