XML 63 R52.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Warrant Liability - Additional Information (Detail) | 1 Months Ended | 9 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Aug. 31, 2016 $ / shares shares | Mar. 31, 2016 USD ($) $ / shares shares | Dec. 31, 2011 $ / shares shares | Sep. 30, 2016 USD ($) $ / shares shares | Sep. 30, 2015 USD ($) | Dec. 31, 2014 USD ($) shares | Dec. 31, 2013 USD ($) shares | Dec. 31, 2012 USD ($) shares | Dec. 31, 2011 USD ($) $ / shares $ / Stock_Unit shares | Jun. 30, 2016 USD ($) | Dec. 31, 2015 USD ($) | Apr. 30, 2015 $ / shares
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fair value of warrant liability | $ |  |  |  | $ 651,902 |  |  |  |  |  | $ 770,964 | $ 770,964 |
Proceeds from issuance of stock units | $ |  |  |  | $ 7,259,613 | $ 24,942,963 |  |  |  |  |  |  |
Dividend yield |  |  |  | 0.00% |  |  |  |  |  |  |  |
Series B Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Term of warrant |  | 5 years |  |  |  |  |  |  |  |  |  |
Number of securities callable by each warrant or right warrants |  | 0.75 |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares | $ 0.30 | $ 5.04 |  |  |  |  |  |  |  |  |  |
Number of additional warrants issued |  | 249,709 |  |  |  |  |  |  |  |  |  |
Number of warrants outstanding | 1,916,407 |  |  |  |  |  |  |  |  |  |  |
Fair value of warrant liability | $ |  |  |  | $ 482,000 |  |  |  |  |  |  |  |
Warrant expiration period |  | 1 year |  |  |  |  |  |  |  |  |  |
Number of warrants surrendered | 1,546,360 |  |  |  |  |  |  |  |  |  |  |
Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by each warrant or right warrants |  | 0.50 |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares | $ 0.30 | $ 3.60 |  |  |  |  |  |  |  |  |  |
Number of warrants exercised | 1,187,190 |  |  |  |  |  |  |  |  |  |  |
Number of additional warrants issued |  | 166,473 |  |  |  |  |  |  |  |  |  |
Proceeds from sale of stock | $ |  |  |  |  |  | $ 1,652,000 | $ 538,000 | $ 3,078,000 |  |  |  |
Number of warrants outstanding | 1,277,609 |  |  |  |  |  |  |  |  |  |  |
Fair value of warrant liability | $ |  |  |  | 115,000 |  |  |  |  |  |  |  |
Warrant expiration period |  | 2 years |  |  |  |  |  |  |  |  |  |
2011 Series A Warrant [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares | $ 0.30 |  |  |  |  |  |  |  |  |  |  |
Number of warrants exercised | 531,814 |  |  |  |  |  |  |  |  |  |  |
Number of shares issued upon warrants exercise | 531,814 |  |  |  |  |  |  |  |  |  |  |
Number of warrants outstanding | 578,081 |  |  |  |  |  |  |  |  |  |  |
Fair value of warrant liability | $ |  |  |  | $ 55,000 |  |  |  |  |  |  |  |
2016 Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares | $ 0.30 |  |  |  |  |  |  |  |  |  |  |
Number of warrants exercised | 1,187,190 |  |  |  |  |  |  |  |  |  |  |
Number of shares issued upon warrants exercise | 1,187,190 |  |  |  |  |  |  |  |  |  |  |
Reduced exercise price of Series A Warrants in exchange for surrender of Series B Warrants | $ / shares | $ 0.30 |  |  |  |  |  |  |  |  |  |  |
Number of warrants outstanding | 1,277,609 |  |  |  |  |  |  |  |  |  |  |
2016 Series B Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares | $ 0.30 |  |  |  |  |  |  |  |  |  |  |
Number of warrants outstanding | 1,916,407 |  |  |  |  |  |  |  |  |  |  |
Number of warrants surrendered | 1,546,360 |  |  |  |  |  |  |  |  |  |  |
Common Stock [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares |  |  |  |  |  |  |  |  |  |  |  | $ 8.40
December 2011 Financing [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of common stock and warrants | $ |  |  |  |  |  |  |  |  | $ 10,000,000 |  |  |
Price per unit | $ / shares |  |  |  |  |  |  |  |  | $ 15.00 |  |  |
Number of Series A warrants in each unit issued in public offering | $ / Stock_Unit |  |  |  |  |  |  |  |  | 1 |  |  |
December 2011 Financing [Member] | Series B Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by warrants |  |  | 666,667 |  |  |  |  |  | 666,667 |  |  |
Term of warrant |  |  | 90 days |  |  |  |  |  | 90 days |  |  |
Warrant expiration date |  |  |  | May 02, 2012 |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares |  |  | $ 15.00 |  |  |  |  |  | $ 15.00 |  |  |
Number of warrants exercised |  |  |  |  |  |  |  | 225,000 |  |  |  |
Number of warrants expired |  |  |  | 441,667 |  |  |  | 441,667 |  |  |  |
December 2011 Financing [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by warrants |  |  | 666,667 |  |  |  |  |  | 666,667 |  |  |
Term of warrant |  |  | 5 years |  |  |  |  |  |  |  |  |
Number of securities callable by each warrant or right warrants |  |  |  | 1 |  |  |  |  |  |  |  |
Number of warrants exercised |  |  |  |  |  | 98,335 | 32,045 | 183,215 |  |  |  |
Number of additional warrants issued |  |  |  |  |  |  |  | 225,000 |  |  |  |
Fair value of warrant liability | $ |  |  |  | $ 54,945 |  |  |  |  |  | $ 770,964 |  |
Dividend yield |  |  |  | 0.00% |  |  |  |  |  |  |  |
December 2011 Financing [Member] | Capital Units [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by warrants |  |  | 666,667 |  |  |  |  |  | 666,667 |  |  |
December 2011 Financing [Member] | Capital Units [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by each warrant or right warrants |  |  | 1 |  |  |  |  |  | 1 |  |  |
December 2011 Financing [Member] | Capital Units [Member] | Series B Warrant [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Warrant expiration period |  |  |  | 2016-12 |  |  |  |  |  |  |  |
December 2011 Financing [Member] | Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by each warrant or right warrants |  |  | 1 | 1 |  |  |  |  | 1 |  |  |
Number of shares issued upon warrants exercise |  |  |  |  |  |  |  | 225,000 |  |  |  |
December 2011 Financing [Member] | Common Stock [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares |  |  | $ 16.80 |  |  |  |  |  | $ 16.80 |  |  |
Number of shares issued upon warrants exercise |  |  |  |  |  | 98,335 | 32,045 | 183,215 |  |  |  |
December 2011 Financing [Member] | Common Stock [Member] | Series B Warrant [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued upon warrants exercise |  |  |  |  |  |  |  | 225,000 |  |  |  |
April 2015 Financing [Member] | Common Stock [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares |  | $ 6.24 |  | $ 6.24 |  |  |  |  |  |  |  | $ 8.40
March 2016 Financing [Member] | Series B Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fair value of warrant liability | $ |  |  |  | $ 482,039 |  |  |  |  |  |  |  |
Dividend yield |  |  |  | 0.00% |  |  |  |  |  |  |  |
March 2016 Financing [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fair value of warrant liability | $ |  |  |  | $ 114,918 |  |  |  |  |  |  |  |
Dividend yield |  |  |  | 0.00% |  |  |  |  |  |  |  |
March 2016 Financing [Member] | Common Stock [Member] | Series A Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants | $ / shares |  | $ 3.60 |  | $ 3.60 |  |  |  |  |  |  |  |
Underwritten Public Offering [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued upon warrants exercise |  | 2,222,250 |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of stock units | $ |  | $ 8,000,000 |  |  |  |  |  |  |  |  |  |
Number of stock units issued, price per share | $ / shares |  | $ 3.60 |  |  |  |  |  |  |  |  |  |
Over-Allotment-Option [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of securities callable by each warrant or right warrants |  | 416,672 |  |  |  |  |  |  |  |  |  |
Number of shares issued upon warrants exercise |  | 333,338 |  |  |  |  |  |  |  |  |  |
Underwriting option exercise period |  | 45 days |  |  |  |  |  |  |  |  |  |

X
- Definition Capital units price per unit + References No definition available. + Details
Name: | stem_CapitalUnitsPricePerUnit
Namespace Prefix: | stem_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class Of Warrant Or Right Exercise Period Of Warrants Or Rights + References No definition available. + Details
Name: | stem_ClassOfWarrantOrRightExercisePeriodOfWarrantsOrRights
Namespace Prefix: | stem_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class Of Warrant Or Right Expiration Period + References No definition available. + Details
Name: | stem_ClassOfWarrantOrRightExpirationPeriod
Namespace Prefix: | stem_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of warrant or right number of securities surrendered. + References No definition available. + Details
Name: | stem_ClassOfWarrantOrRightNumberOfSecuritiesSurrendered
Namespace Prefix: | stem_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of warrant or right number of warrants or rights exercised + References No definition available. + Details
Name: | stem_ClassOfWarrantOrRightNumberOfWarrantsOrRightsExercised
Namespace Prefix: | stem_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of warrant or right number of warrants or rights expired + References No definition available. + Details
Name: | stem_ClassOfWarrantOrRightNumberOfWarrantsOrRightsExpired
Namespace Prefix: | stem_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of warrant or right number of warrants or rights issued. + References No definition available. + Details
Name: | stem_ClassOfWarrantOrRightNumberOfWarrantsOrRightsIssued
Namespace Prefix: | stem_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of Warrants Expiration Month and Year + References No definition available. + Details
Name: | stem_ClassOfWarrantsExpirationMonthAndYear
Namespace Prefix: | stem_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of warrant liability. + References No definition available. + Details
Name: | stem_FairValueOfWarrantLiability
Namespace Prefix: | stem_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Proceeds From Issuance Of Common Stock And Warrants + References No definition available. + Details
Name: | stem_ProceedsFromIssuanceOfCommonStockAndWarrants
Namespace Prefix: | stem_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Public Offered Units Series Warrants Issued Per Unit + References No definition available. + Details
Name: | stem_PublicOfferedUnitsSeriesWarrantsIssuedPerUnit
Namespace Prefix: | stem_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reduced exercise price of class of warrant in exchange for surrender of another class of warrant. + References No definition available. + Details
Name: | stem_ReducedExercisePriceOfClassOfWarrantInExchangeForSurrenderOfAnotherClassOfWarrant
Namespace Prefix: | stem_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Underwriting option exercise period. + References No definition available. + Details
Name: | stem_UnderwritingOptionExercisePeriod
Namespace Prefix: | stem_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the warrants or rights are exercisable, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(3)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ClassOfWarrantOrRightLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares. + References No definition available. + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedDividendRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Cash received on stock transaction after deduction of issuance costs. + References No definition available. + Details
Name: | us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Per share or per unit amount of equity securities issued. + References No definition available. + Details
Name: | us-gaap_SharesIssuedPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of new stock issued during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=stem_SeriesBWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=stem_SeriesAWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=stem_TwoThousandElevenSeriesAWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=stem_TwoThousandAndSixteenSeriesAWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=stem_TwoThousandAndSixteenSeriesBWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=stem_DecemberTwoThousandElevenFinancingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CapitalUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=stem_SeriesBWarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=stem_AprilTwoThousandFifteenFinancingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=stem_MarchTwoThousandSixteenFinancingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=stem_UnderwrittenPublicOfferingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |