Document and Entity Information Document Information [Table] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] ADR [Member] ADS Common Class A [Member] Class A Ordinary Shares Common Class B [Member] Class B Ordinary Shares Entity Addresses, Address Type [Axis] Address Type [Domain] Business Contact [Member] Business Contact Document Information [Line Items] Document Information Document Type Document Registration Statement Document Annual Report Document Period End Date Document Transition Report Document Shell Company Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Address, Address Line One Entity Address, City or Town Entity Address, Country Country Region Local Phone Number Contact Personnel Email Address Title of 12(b) Security Trading Symbol Security Exchange Name Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Emerging Growth Company ICFR Auditor Attestation Flag Document Financial Statement Error Correction [Flag] Document Accounting Standard Entity Shell Company Contact Personnel Name Auditor Firm ID Auditor Name Auditor Location Entity Central Index Key Document Fiscal Year Focus Current Fiscal Year End Date Document Fiscal Period Focus Amendment Flag No Trading Symbol Flag CONSOLIDATED BALANCE SHEETS Statement [Table] Statement [Line Items] Statement Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash of continuing operation at the end of the year Cash and cash equivalents Accounts Receivable, Net, Current Accounts receivable, net Accounts receivable, net Inventories Prepaid Expense and Other Assets, Current Total prepayments and other current assets Prepayments and other current assets Disposal Group, Including Discontinued Operation, Assets, Current Current assets of discontinued operation Current assets of discontinued operations Assets, Current Total current assets Assets, Noncurrent [Abstract] Non-current assets: Goodwill Goodwill Intangible Assets, Net (Excluding Goodwill) Intangible assets, net Property, Plant and Equipment, Net Property, equipment and software, net Operating Lease, Right-of-Use Asset Operating right-of-use assets, net Other Assets, Noncurrent Other non-current assets Disposal Group, Including Discontinued Operation, Assets, Noncurrent Non-current assets of discontinued operations Non-current assets of discontinued operations Assets, Noncurrent Total non-current assets Assets TOTAL ASSETS Total assets Liabilities [Abstract] LIABILITIES Liabilities, Current [Abstract] Current liabilities: Short-term Debt Short-term borrowing Short-term borrowing Accounts Payable, Current Accounts payable Carrying amount as of the balance sheet date of accrued expenses and other liabilities. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer). Accrued Expenses and Other Liabilities, Current Accrued expenses and other liabilities Total Operating Lease, Liability, Current Operating lease liabilities, current Disposal Group, Including Discontinued Operation, Liabilities, Current Current liabilities of discontinued operations (including amounts of consolidated VIEs of US$47,545 and nil, respectively) Current liabilities of discontinued operations Current liabilities of discontinued operations Liabilities, Current Total current liabilities Liabilities, Noncurrent [Abstract] Non-current liabilities: Long-Term Debt, Excluding Current Maturities Long-term borrowing Operating Lease, Liability, Noncurrent Operating lease liabilities, non-current Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent Non-current liabilities of discontinued operations (including amounts of consolidated VIEs of US$727 and nil, respectively) Non-current liabilities of discontinued operations Non-current liabilities of discontinued operations Liabilities, Noncurrent Total non-current liabilities Liabilities Total liabilities TOTAL LIABILITIES Commitments and Contingencies. Commitments and contingencies (Note 16) Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] SHAREHOLDERS' (DEFICIT)/EQUITY Common Stock, Value, Issued Ordinary shares Additional Paid in Capital Additional paid-in capital Amount of Statutory reserves to be maintained by the company. Statutory Reserves Statutory reserves Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income/(loss) Retained Earnings (Accumulated Deficit) Accumulated deficit Retained earnings Stockholders' Equity Attributable to Parent Total shareholders' (deficit)/equity Stockholders' Equity Attributable to Noncontrolling Interest Non-controlling interests Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance at end of year Balance at beginning of year TOTAL (DEFICIT)/EQUITY Liabilities and Equity TOTAL LIABILITIES AND (DEFICIT)/EQUITY Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Variable Interest Entity, Primary Beneficiary [Member] Consolidated VIEs Common Stock, Par or Stated Value Per Share Ordinary shares par value (in dollars per share) Common Stock, Shares Authorized Ordinary shares authorized (in shares) Common Stock, Shares, Outstanding Ordinary shares outstanding (in shares) Common Stock, Shares, Issued Balance at end of year (in shares) Balance at beginning of year (in shares) Ordinary shares issued (in shares) CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Cost of Sales [Member] Cost of revenues Selling and Marketing Expense [Member] Sales and marketing expenses General and Administrative Expense [Member] General and administrative expenses Research and Development Expense [Member] Research and development expenses Revenue from Contract with Customer, Excluding Assessed Tax Revenues The aggregate cost (reversal) of revenues rendered during the reporting period. Revenues, Cost (Reversal) Cost of revenues Gross Profit Gross profit Operating Expenses [Abstract] Operating expenses: The aggregate total amount of expenses (reversal) directly related to the marketing or selling of products or services. Sales and Marketing Expenses (Reversal) Sales and marketing expenses General and Administrative Expense General and administrative expenses Amount of expense (reversal) for research and development. Includes, but is not limited to, cost for computer software product to be sold, leased, or otherwise marketed and writeoff of research and development assets acquired in transaction other than business combination or joint venture formation or both. Excludes write-down of intangible asset acquired in business combination or from joint venture formation or both, used in research and development activity. Research and Development Expenses (Reversal) Research and development expenses Operating Expenses Total operating income/(expenses) Operating Income (Loss) Operating income/ (loss) Gain (Loss) on Disposition of Business Loss from disposal of subsidiaries Gain (loss) on disposal of SCHL Group Loss from disposal of subsidiaries Interest Income (Expense), Nonoperating, Net Interest expenses, net Other Nonoperating Income (Expense) Other (expenses)/income, net Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Loss before income tax expense Loss before income tax expense Income Tax Expense (Benefit) Income tax benefit Total income tax benefit Total income tax benefit Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net loss from continued operations Net loss from continuing operations Net loss from continuing operations Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: net loss from discontinued operations Net loss from discontinued operations, net of income tax Net loss from discontinued operations, net of income tax Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss Net loss Net loss from operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest Net loss from continuing operations attributable to non-controlling interests Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest Net (loss)/income from discontinued operations attributable to non-controlling interests Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Net loss from continuing operations attributable to J and Friends Holdings Limited shareholders Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Net loss from discontinued operations attributable to J and Friends Holdings Limited shareholders Assessable profits Net loss attributable to J and Friends Holdings Limited shareholders Net (loss)/profit Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive income/(loss): Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation adjustments, net of nil tax Other Comprehensive Income (Loss), Net of Tax Total other comprehensive income/(loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Total comprehensive (loss)/income attributable to non-controlling interest Comprehensive Income (Loss), Net of Tax, Attributable to Parent Total comprehensive loss attributable to J and Friends Holdings Limited shareholders Earnings Per Share, Pro Forma [Abstract] Loss per ordinary share Income (Loss) from Continuing Operations, Per Basic Share Continued operations - basic Basic net loss per share from continuing operations attributable to ordinary shareholders Income (Loss) from Continuing Operations, Per Diluted Share Continued operations - diluted Diluted net loss per share from continuing operations attributable to ordinary shareholders Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Discontinued operations - basic Basic net loss per share from discontinued operations attributable to ordinary shareholders Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Discontinued operations - diluted Diluted net loss per share from discontinued operations attributable to ordinary shareholders Earnings Per Share, Basic Total net loss per ordinary shares - basic Earnings Per Share, Diluted Total net loss per ordinary shares - diluted No Definition Available. Weighted Average Shares Outstanding Pro Forma [Abstract] Weighted average number of ordinary shares outstanding Weighted Average Number of Shares Outstanding, Basic and Diluted Basic (In shares) Weighted average ordinary shares outstanding-basic Weighted Average Number of Shares Outstanding, Diluted Diluted (In shares) Weighted average ordinary shares outstanding-diluted Share-based Compensation, Allocation and Classification in Financial Statements [Abstract] Share-based compensation expenses included in Allocated Share-based Compensation Expense Share-based compensation expenses Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Foreign currency translation adjustments, tax CONSOLIDATED STATEMENTS OF CHANGES IN (DEFICIT)/EQUITY Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Ordinary shares This member stands for statutory reserve. Statutory Reserve [Member] Statutory Reserve Additional Paid-in Capital [Member] Additional Paid-in Capital AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income Retained Earnings [Member] Accumulated Deficit Parent [Member] Parent company Noncontrolling Interest [Member] Non-controlling Interest Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption, Adjustment [Member] Cumulative Effect, Period of Adoption, Adjustment Impact of Adoption of ASC 326 Increase (Decrease) in Stockholders' Equity [Roll Forward] Changes in equity Stock Issued During Period, Value, New Issues Issuance of Class A Ordinary Shares Stock Issued During Period, Shares, New Issues Issuance of Class A Ordinary Shares (in shares) Stock Issued During Period, Value, Stock Options Exercised Exercise of options Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercised (shares) Exercise of options (in shares) Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Share-based awards to employee of the Group Stock Issued During Period, Value, Acquisitions Issuance of Class A ordinary shares for business acquisition Stock Issued During Period, Shares, Acquisitions Issuance of Class A ordinary shares for business acquisition (in shares) Value of ordinary shares reclassified between classes. Reclassification Between Classes of Ordinary Shares, Value Conversion from Class B ordinary shares to Class A ordinary shares Number of ordinary shares reclassified between classes. Reclassification Between Classes of Ordinary Shares Conversion from Class B ordinary shares to Class A ordinary shares (in shares) Amount of increase (decrease) in equity for disposal of discontinued operations. Disposal of Discontinued Operations, Increase (Decrease) in Equity Disposal of discontinued operations The amount of appropriation to statutory reserve. Appropriation to Statutory Reserve Appropriation to statutory reserve Amount of increase in additional paid in capital from disposal of subsidiary. Adjustments to Additional Paid in Capital, Increase from Disposal of Subsidiary Disposal of SCHL Group Amount of decrease in additional paid in capital from prior year adjustment. Adjustments to Additional Paid in Capital, Prior Year Adjustment Prior year adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Foreign currency translation adjustments, net of nil tax CONSOLIDATED STATEMENTS OF CASH FLOWS Schedule of Business Acquisitions, by Acquisition [Table] Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net loss to net cash (used in)/provided by operating activities: Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Operating Lease, Right-of-Use Asset, Periodic Reduction Amortization of operating lease right-of-use assets Share-based Compensation Share-based compensation (reversal)/expense Share-based compensation expenses It represents Provision for doubtful accounts and credit losses. Provision For Doubtful Accounts and Credit Losses Provision for credit losses Deferred Income Tax Expense (Benefit) Total deferred income tax benefit Deferred taxes Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) in Prepaid Expense and Other Assets Prepayments and other current assets Increase (Decrease) in Inventories Inventories Increase (Decrease) in Accounts Payable, Trade Accounts payable Increase (Decrease) in Operating Lease Liability Operating lease liabilities The increase (decrease) during the period in the amount of Accrued expenses and other liabilities. Increase (Decrease) in Accrued Expenses and Other Liabilities Accrued expenses and other liabilities Cash Provided by (Used in) Operating Activity, Continuing Operation Net cash used in operating activities from continuing operations Net cash used in operating activities from continuing operations Cash Provided by (Used in) Operating Activity, Discontinued Operation Net cash provided by/(used in) operating activities from discontinued operations