v3.26.3
Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Class of Stock [Line Items]    
Total stock-based compensation for the period $ 3,360 $ 10,093
Stock-based compensation recognized in APIC 6,692 8,454
Share-Based Payment Arrangement, Expense 3,360 10,093
Employee Stock Option Plans (ESOP) [Member]    
Class of Stock [Line Items]    
Total stock-based compensation for the period (615) 131
Share-Based Payment Arrangement, Expense (615) 131
non-ESOP Option Agreements [Member]    
Class of Stock [Line Items]    
Total stock-based compensation for the period 5 27
Share-Based Payment Arrangement, Expense 5 27
SEALSQ Option Plans [Member]    
Class of Stock [Line Items]    
Total stock-based compensation for the period 3,970 9,935
Share-Based Payment Arrangement, Expense 3,970 9,935
Research and Development Expenses [Member]    
Class of Stock [Line Items]    
Stock-based compensation recognized in APIC 543 1,834
Selling and Marketing Expenses [Member]    
Class of Stock [Line Items]    
Stock-based compensation recognized in APIC 278 3,134
General and Administrative Expenses [Member]    
Class of Stock [Line Items]    
Stock-based compensation recognized in APIC $ 2,539 $ 5,125