XML 41 R30.htm IDEA: XBRL DOCUMENT
v3.19.2

The Company and its Significant Accounting Policies - Additional Information (Details) $ in Thousands | Nov. 02, 2018 | Mar. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
--- | --- | --- | ---
Company And Significant Accounting Policies [Line Items] |  |  |
Reverse stock split ratio | 0.0667 |  |
IPO |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |
Deferred offering costs |  | $ 1,709 | $ 63

X
- Definition Company and significant accounting policies. + References No definition available. + Details
Name: | sonm_CompanyAndSignificantAccountingPoliciesLineItems
Namespace Prefix: | sonm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Specific incremental costs directly attributable to a proposed or actual offering of securities which are deferred at the end of the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.A) -URI http://asc.fasb.org/extlink&oid=27011391&loc=d3e105025-122735 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DeferredOfferingCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB TOPIC 4.C) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770 + Details
Name: | us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

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