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Stock-based compensation - Narrative (Details) - USD ($) $ in Thousands				3 Months Ended		9 Months Ended		12 Months Ended
	Apr. 05, 2022	Apr. 05, 2019	Apr. 11, 2012	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2012	May 09, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation cost				$ 21,994	$ 19,516	$ 63,335	$ 46,381
Options granted, contractual period, years						10 years
Options granted (in shares)						0	0
Unrecognized stock-based compensation cost for options				2,060		$ 2,060
Restricted stock unit vesting right (in shares)						1
Restricted stock unit vesting right, fair value (in shares)						1
Performance units vesting right (in shares)						1
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining requisite vesting period						10 months 24 days
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining requisite vesting period						2 years
Vested, number of shares (in shares)						810,027
Net settlement on vesting of restricted share unit (in shares)						502,558
Unrecognized stock-based compensation cost				56,833		$ 56,833
Restricted Stock Units (RSUs) | Vesting Period Two Thousand Twenty Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, number of shares (in shares)								22,551
Net settlement on vesting of restricted share unit (in shares)						13,626
Restricted Stock Units (RSUs) | Vesting Period Two Thousand Twenty Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, number of shares (in shares)									47,193
Net settlement on vesting of restricted share unit (in shares)						46,982
Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining requisite vesting period						1 year 10 months 24 days
Vested, number of shares (in shares)						1,154,998
Unrecognized stock-based compensation cost				$ 62,212		$ 62,212
Vested, net of withholding tax (in shares)						738,490
Performance Units | Prior to 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance units vesting right, fair value (in shares)						1
Performance units period						1 year
Performance Units | 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance units period						3 years
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per share allowed to eligible employees to purchase through payroll deductions (in percentage)						90.00%
Maximum percentage of employee's base salary allowed to be purchased (in percentage)				15.00%		15.00%
Maximum dollar amount of common shares allowed to be purchased						$ 25
Common shares reserved for issuance (in shares)				4,200,000		4,200,000
Issuance of common shares under the employee stock purchase plan (in shares)						178,811	261,281
Compensation expense for ESPP				$ 227	$ 210	$ 720	$ 895
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period						3 years
Minimum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period						3 months
Minimum | Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period						6 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period						5 years
Maximum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period						4 years
Maximum | Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period						3 years
2007 Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amended omnibus plan, increase in number of common shares authorized for issuance (in shares)	3,500,000	8,000,000	5,593,200							8,858,823
Number of common shares authorized for issuance (in shares)	26,500,000	23,000,000	15,000,000
2017 Omnibus Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares authorized for issuance (in shares)											15,000,000

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