Share Compensation Plans - Narrative (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 11,258	$ 9,172	$ 14,562
Unamortized future compensation expense	$ 1,500
Restricted Stock, subject to time-based criteria \| Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	25.00%
Time-Based Restricted Stock Units settled in stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 7,500	6,900	10,900
Unamortized future compensation expense	6,900
Tax benefit related to compensation expense	$ 1,600	1,300	500
Time-Based Restricted Stock Units settled in stock \| Minimum \| Officer \| Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Time-Based Restricted Stock Units settled in stock \| Maximum \| Officer \| Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Performance-Based Restricted Stock, earned
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 1,900	1,400	2,800
Performance period	1 year
Tax benefit related to compensation expense	$ 200	200	100
Performance-Based Restricted Stock, earned \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	1 year
Restricted Stock, subject to performance criteria
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized future compensation expense	$ 1,200
Market-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	1,800	700	600
Tax benefit related to compensation expense	$ 100	$ 100	$ 100
Market-Based Restricted Stock Units \| Tranche Two \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
2019 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation awards issued (in shares)	2.1
Percentage of shares issued and outstanding	6.00%

OneSpan Inc. 10-K