XML 14 R1.htm IDEA: XBRL DOCUMENT v3.21.2
Cover - shares
 6 Months Ended
Jun. 30, 2021
Aug. 10, 2021
Entity Listings [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2021  
Document Transition Report false  
Entity Registrant Name STEM, INC.  
Entity Incorporation, State or Country Code DE  
Entity File Number 333-251397  
Entity Tax Identification Number 85-1972187  
Entity Address, Address Line One 100 California St., 14th Fl  
Entity Address, City or Town San Francisco  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94111  
Country Region 1  
City Area Code 877  
Local Phone Number 374-7836  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   131,008,933
Entity Central Index Key 0001758766  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Common Stock    
Entity Listings [Line Items]    
Title of 12(b) Security Common Stock, par value $0.0001  
Trading Symbol STEM  
Security Exchange Name NYSE  
Common Stock Warrants    
Entity Listings [Line Items]    
Title of 12(b) Security Warrants, each whole warrant exercisable for Common Stock at an exercise price of $11.50 per share  
Trading Symbol STEM WS  
Security Exchange Name NYSE