v3.26.1
WARRANTY - Accrual Balance in BS (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
WARRANTY        
Accrual for product warranties $ 12,958 $ 12,819 $ 12,913 $ 12,300
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent        
WARRANTY        
Accrual for product warranties 7,700      
Location, Statement of Financial Position, Balance [Axis]: rbbn:AccruedLiabilitiesAndOtherLiabilitiesCurrent        
WARRANTY        
Accrual for product warranties $ 5,300