Quarterly report [Sections 13 or 15(d)]

Summary of Significant Accounting Policies - Narrative (Details)

v3.26.3
Summary of Significant Accounting Policies - Narrative (Details)
$ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2025
USD ($)
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Dec. 18, 2025
right
Dec. 17, 2025
right
Class of Stock [Line Items]                
Accumulated deficit $ (660,229) $ (662,056)   $ (662,056)   $ (660,229)    
Cash and cash equivalents $ 8,490 7,988 $ 8,907 7,988 $ 8,907 8,490    
Customer loyalty program, rewards points expiration period 13 months              
Deferred revenue $ 5,033 6,578   6,578   5,033    
Contract with customer, material rights | right             3 2
Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:ContractWithCustomerLiabilityCurrent                
Class of Stock [Line Items]                
Contract with customer, liability, revenue recognized       4,700 $ 5,900      
Balance Sheet Location [Axis]: us-gaap:ContractWithCustomerLiabilityCurrent                
Class of Stock [Line Items]                
Deferred revenue 4,800 4,000   4,000   4,800    
Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesCurrent                
Class of Stock [Line Items]                
Deferred revenue 0 0   0   0    
Green Rewards                
Class of Stock [Line Items]                
Deferred revenue $ 200 $ 2,200   $ 2,200   $ 200    
Cost of Goods and Service, Product and Service Benchmark | Supplier Concentration Risk | Five Suppliers                
Class of Stock [Line Items]                
Concentration risk, percentage   30.00% 40.00% 30.00% 40.00%      
Customer One | Accounts Receivable | Customer Concentration Risk                
Class of Stock [Line Items]                
Concentration risk, percentage       76.00%   82.00%    
Customer Two | Accounts Receivable | Customer Concentration Risk                
Class of Stock [Line Items]                
Concentration risk, percentage       14.00%