v3.26.1
INCOME TAXES - Additional Information (Details)
$ in Thousands
 12 Months Ended
Oct. 11, 2014
Jan. 01, 2008
Dec. 31, 2025
USD ($)
Item
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2020
USD ($)
INCOME TAXES            
Intercompany dividend incomes     $ 12,800   $ 15,400  
Ending balance—gross unrecognized tax benefits (“UTB”s)     3,244 $ 3,244 3,244  
Income tax paid     800      
Unrecognized tax benefits if recognized, would impact certain deferred tax assets     2,700     $ 2,700
Unrecognized tax benefits that would impact the annual effective tax rate if recognized     541 541 541  
Accrued interest and penalties     500      
Net operating loss carryforwards     546,000      
Change in deferred tax valuation allowance     (3,700) (2,203) (2,369)  
Income tax benefit related to tax credits     $ 0 $ 0 $ 0  
Income tax benefit (expense) computed at US tax rate     21.00%      
U.S Federal            
INCOME TAXES            
Net operating loss carryforwards     $ 548,000      
Net operating loss carryforwards indefinitely     2,000      
Valuation allowance against the related deferred tax assets     1,900      
U.S Federal | Research and development credit carryforwards            
INCOME TAXES            
Tax credit carryforwards     1,200      
Tax Credit Carry Forward Amount Not Subject To Expiration     6,400      
Tax Credit Carry Forward Amount Subject To Expiration     1,200      
State            
INCOME TAXES            
Net operating loss carryforwards     228,000      
U.S Federal and State            
INCOME TAXES            
Valuation allowance against the related deferred tax assets     128,900      
Foreign            
INCOME TAXES            
Tax credit carryforwards     $ 5,500      
Earliest Tax Year | U.S Federal            
INCOME TAXES            
Operating loss carryforwards expiration year     2026      
Tax credit carryforward expiration year     2026      
Earliest Tax Year | U.S Federal | Research and development credit carryforwards            
INCOME TAXES            
Tax credit carryforward expiration year     2026      
Earliest Tax Year | State            
INCOME TAXES            
Operating loss carryforwards expiration year     2028      
Latest Tax Year | U.S Federal            
INCOME TAXES            
Operating loss carryforwards expiration year     2037      
Tax credit carryforward expiration year     2028      
Latest Tax Year | U.S Federal | Research and development credit carryforwards            
INCOME TAXES            
Tax credit carryforward expiration year     2028      
Latest Tax Year | State            
INCOME TAXES            
Operating loss carryforwards expiration year     2033      
CAYMAN ISLANDS            
INCOME TAXES            
Withholding tax     $ 0      
China            
INCOME TAXES            
Foreign statutory tax rate (as a percent)     25.00%      
Reduced tax rate for qualified high technology enterprises (as a percent)     15.00%      
China | U T Starcom Telecom Co Ltd            
INCOME TAXES            
Reduced tax rate for qualified high technology enterprises (as a percent) 15.00% 15.00%        
Number of subsidiaries approved for the reduced tax rate | Item     1      
Valid period for reduced income tax rate applicable to qualified high technology enterprise 3 years 3 years        
China | Foreign            
INCOME TAXES            
Net operating loss carryforwards     $ 130,100      
Net operating loss carryforwards expired     12,800      
Valuation allowance against the related deferred tax assets     $ 19,800      
China | Earliest Tax Year | Foreign            
INCOME TAXES            
Operating loss carryforwards expiration year     2026      
China | Latest Tax Year | Foreign            
INCOME TAXES            
Operating loss carryforwards expiration year     2035      
Countries other than the U.S. and China | Foreign            
INCOME TAXES            
Net operating loss carryforwards     $ 94,400      
Valuation allowance against the related deferred tax assets     15,800      
California | State | Research and development credit carryforwards            
INCOME TAXES            
Tax credit carryforwards     $ 6,400