Stock-based compensation - Narrative (Details) $ / shares in Units, $ in Millions				1 Months Ended	7 Months Ended	12 Months Ended
	Mar. 07, 2024 $ / shares	Jan. 01, 2021 shares	Dec. 28, 2015 shares	Sep. 30, 2020 period shares	Oct. 31, 2024 employee	Dec. 31, 2024 USD ($) $ / shares shares	Jan. 01, 2025 shares	Dec. 31, 2023 shares	Feb. 28, 2023 shares	Jan. 31, 2023 shares	Feb. 28, 2022 shares	Jan. 31, 2022 shares	Jan. 01, 2022 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized (in shares)						150,000,000		150,000,000
Common stock, shares outstanding						70,625,899		60,467,188
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs | $						$ 1.2
Expected to be recognized over a weighted average period						2 months 12 days
Stock-based compensation, shares authorized for issuance											563,500	563,500
Share-based compensation, number of common stock issuable per RSU vested						1
Time-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs | $						$ 7.7
Expected to be recognized over a weighted average period						2 years 10 months 24 days
Stock-based compensation, shares authorized for issuance									824,600	824,600
Share-based compensation, number of common stock issuable per RSU vested						1
2015 Incentive Stock Option and Grant Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares reserved for issuance			2,525,327
Cliff vesting period			1 year
Contractual life of options from the date of grant			10 years
Common stock shares available for issuance (in shares)						3,281,795
2015 Incentive Stock Option and Grant Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period			5 years
2015 Incentive Stock Option and Grant Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period			8 years
2020 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares reserved for issuance				6,567,144
Common stock shares available for issuance (in shares)						3,281,795
Options granted (in dollars per share) | $ / shares	$ 22.00					$ 6.83
Tranche two exercise price (in dollars per share) | $ / shares	11.88
Tranche one exercise price (in dollars per share) | $ / shares	$ 19.00
Incremental cost of plan modification | $						$ 1.2
Unrecognized compensation costs | $						$ 25.0
Expected to be recognized over a weighted average period						2 years
Percentage of outstanding shares of common stock		5.00%
2020 Stock Option and Incentive Plan | Subsequent event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized (in shares)							3,531,294
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares reserved for issuance						2,166,905
Common stock, shares authorized (in shares)													656,714
Maximum authorized payroll deduction percentage of eligible compensation for eligible employees				15.00%
Number of annual offering periods (or more) | period				1
Shares issued under employee stock purchase plan (in shares)						110,895
Percentage of outstanding shares of common stock		1.00%
Common stock, shares outstanding		656,714
Inducement Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period					4 years
Options granted (in dollars per share) | $ / shares						$ 6.00
Unrecognized compensation costs | $						$ 3.5
Expected to be recognized over a weighted average period						3 years 4 months 24 days
Number of employees granted non-qualified stock options | employee					3
Inducement Grants | Share-Based Payment Arrangement, Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage					25.00%
Inducement Grants | Share-Based Payment Arrangement, Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage					25.00%
Inducement Grants | Share-Based Payment Arrangement, Tranche Three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage					25.00%
Inducement Grants | Share Based Compensation Award, Tranche Four
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage					25.00%