Cover [Abstract] Document Information [Table] Document Information [Line Items] Document Type Amendment Flag Document Registration Statement Document Annual Report Document Transition Report Document Shell Company Report Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Common Stock, Shares Outstanding Entity Shell Company Entity Emerging Growth Company Title of 12(b) Security Trading Symbol No Trading Symbol Flag Security Exchange Name Entity Interactive Data Current Document Accounting Standard Entity File Number Entity Incorporation, State or Country Code Contact Personnel Name Entity Address, Address Line One Entity Address, Address Line Two Entity Address, City or Town Entity Address, Postal Zip Code Entity Address, Country City Area Code Local Phone Number ICFR Auditor Attestation Flag Extension Auditor Name Auditor Firm ID Auditor Location Class of Stock [Axis] Class of Stock [Domain] ADR [Member] American Depositary Shares [Member] Common Stock [Member] Ordinary Shares [Member] Entity Addresses, Address Type [Axis] Address Type [Domain] Business Contact [Member] Statement of Financial Position [Abstract] CONSOLIDATED BALANCE SHEETS Statement [Table] Schedule Of Finite Lived Intangible Assets Table Statement [Line Items] Assets [Abstract] Assets ASSETS Assets, Current [Abstract] Current assets: Accounts Receivable, after Allowance for Credit Loss, Current Accounts receivable, net of allowance for credit losses of RMB15,770 and RMB32,265 (US$5,063) as of December 31, 2020 and 2021, respectively Accounts receivable, net of allowance for credit losses of RMB15,745 and RMB30,082 (US$4,721) as of December 31, 2020 and 2021, respectively Accounts receivable, net Due from Related Parties, Current Amounts due from related parties Prepaid Expense and Other Assets, Current Prepayments and other assets Prepayments and other assets Total Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash, cash equivalents, and restricted cash at beginning of year Cash, cash equivalents, and restricted cash at end of year Assets, Current Total current assets Short-term Investments Short-term investments Restricted Cash, Current Restricted cash Assets Total assets Assets, Noncurrent [Abstract] Non-current assets: Property, Plant and Equipment, Net Property and equipment, net Property and equipment, net Intangible Assets, Net (Excluding Goodwill) Intangible assets, net Assets, Noncurrent Total non-current assets Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Due from Related Parties, Noncurrent Amounts due from related parties Equity Method Investments Equity investments Prepaid Expense and Other Assets, Noncurrent Prepayments and other assets Prepayments and other assets Total Deferred Income Tax Assets, Net Deferred tax assets Goodwill Goodwill Goodwill Ending balance Beginning balance Liabilities and Equity [Abstract] LIABILITIES, NON-CONTROLLING INTEREST, AND SHAREHOLDERS' EQUITY LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities, Current [Abstract] Current liabilities: Current liabilities: Short-term Debt Short-term bank loans (including short-term bank loans of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB278,488 and RMB1,348,166 (US$211,557) as of December 31, 2020 and 2021, respectively) Short-term bank loans Short-term Debt, Current Long-term Debt, Current Maturities Long-term bank loan, current portion (including long-term bank loan, current portion of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB74,351 and RMB nil (US$ nil) as of December 31, 2020 and 2021, respectively) Long-term bank loan, current portion Current portion Accounts Payable, Current Accounts payable (including accounts payable of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB2,013,428 and RMB2,733,487 (US$428,944) as of December 31, 2020 and 2021, respectively) Accounts payable Liabilities, Current Total current liabilities Accounts payable Accrued expenses and other liabilities Current Accrued expenses and other liabilities (including accrued expenses and other liabilities of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB521,307 and RMB1,208,868 (US$189,698) as of December 31, 2020 and 2021, respectively) Accrued expenses and other current liabilities Accrued expenses and other liabilities Current. Accrued Income Taxes, Current Income tax payable (including income tax payable of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB45 and RMB1,026 (US$161) as of December 31, 2020 and 2021, respectively) Income tax payable Operating Lease, Liability, Current Current operating lease liabilities (including current operating lease liabilities of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB56,261 and RMB70,672 (US$11,090) as of December 31, 2020 and 2021, respectively) Current operating lease liabilities Due to Related Parties, Current Amounts due to related parties (including amounts due to related parties of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB56,795 and RMB797,731 (US$125,181) as of December 31, 2020 and 2021, respectively) Amounts due to related parties Liabilities and Equity Total liabilities, non-controlling interests and shareholders' equity Commitments and Contingencies Commitments and contingencies Liabilities, Noncurrent [Abstract] Non-current liabilities: Non-current liabilities Operating Lease, Liability, Noncurrent Non-current operating lease liabilities (including non-current operating lease liabilities of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB146,012 and RMB121,057 (US$18,996) as of December 31, 2020 and 2021, respectively) Non-current operating lease liabilities Deferred Income Tax Liabilities, Net Deferred tax liabilities (including deferred tax liabilities of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB29 and RMB nil (US$ nil) as of December 31, 2020 and 2021, respectively) Deferred tax liabilities Liabilities, Noncurrent Total non-current liabilities Liabilities Total liabilities Other Liabilities, Noncurrent Other liabilities (including other liabilities of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB7,020 and RMB6,975 (US$1,095) as of December 31, 2020 and 2021, respectively) Other liabilities Due to Related Parties, Noncurrent Amounts due to related parties (including amounts due to related parties of the consolidated VIEs and their subsidiaries without recourse to the primary beneficiary of RMB nil and RMB472,882 (US$74,206) as of December 31, 2020 and 2021, respectively) Amounts due to related parties Amounts due to related parties Sharehold Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]ers' (deficit) equity: Shareholders' equity: Shareholders' (deficit) equity: Additional Paid in Capital Additional paid-in capital Stockholders' Equity Attributable to Noncontrolling Interest Non-controlling interests Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Beginning Balance Ending Balance Accumulated other comprehensive income Stockholders' Equity Attributable to Parent Total Kingsoft Cloud Holdings Limited shareholders' equity Common Stock, Value, Issued Ordinary shares (par value of US$0.001 per share; 4,000,000,000 and 40,000,000,000 shares authorized, 3,546,124,955 and 3,805,284,810 shares issued, 3,339,618,633 and 3,646,477,840 shares outstanding as of December 31, 2020 and 2021, respectively) Ordinary shares Retained Earnings (Accumulated Deficit) Accumulated deficit Increase in accumulated deficit Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total equity Balance Balance Accounts Receivable, Allowance for Credit Loss Accounts receivable, net Common stock shares authorised Common stock shares authorised Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Common stock, par or stated value per share Common Stock, Shares, Issued Common Stock, Shares, Issued Common stock, shares, issued Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Common stock, shares, outstanding Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] Income Statement [Abstract] Product and Service [Axis] Product and Service [Domain] Other Services [Member] Others [Member] Public cloud service [Member] Public cloud services [Member] Public cloud service. Enterprise Cloud Services [Member] Enterprise cloud services [Member] Enterprise Cloud Services [Member] Operating Expenses [Abstract] Operating expenses: Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Loss before income taxes Loss before income tax Other Nonoperating Income (Expense) Other income (expense), net Other (expenses) income, net Selling and Marketing Expense Selling and marketing expenses Foreign Currency Transaction Gain (Loss), before Tax Foreign exchange (loss) gain Foreign exchange loss (gain) Foreign exchange (loss) gain Net Income (Loss) Available to Common Stockholders, Basic Net loss attributable to ordinary shareholders Interest Expense Interest expense Income Tax Expense (Benefit) Income tax expense Income tax expense Net loss Net loss Net (loss) profit for the year Net loss Operating Income (Loss) Operating loss Net Income (Loss) Attributable to Parent Net loss attributable to Kingsoft Cloud Holdings Limited Net loss Net loss attributable to Kingsoft Cloud Holdings Limited Other Nonoperating Gains (Losses) Other gain, net Investment Income, Interest Interest income Net Income (Loss) Attributable to Noncontrolling Interest Less: net income (loss) attributable to non-controlling interests Operating Expenses Total operating expenses General and Administrative Expense General and administrative expenses Temporary Equity, Accretion to Redemption Value, Adjustment Accretion to redemption value of redeemable convertible preferred shares Research and Development Expense Research and development expenses Revenues [Abstract] Revenues: Revenues Cost of Revenue Cost of revenues (including related party amounts of RMB660, RMB988 and RMB2,194 (US$344) for the years ended December 31, 2019, 2020 and 2021, respectively) Gross Profit Gross profit Supplemental Income Statement Elements [Abstract] Other comprehensive income (loss), net of tax of nil: Foreign currency translation adjustments Foreign currency translation adjustments Comprehensive Income Loss Net Of Tax Attributable To Common Stockholders Basic Comprehensive loss attributable to ordinary shareholders Comprehensive income loss net of tax attributable to common stockholders basic. Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Less: Comprehensive income (loss) attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive loss attributable to Kingsoft Cloud Holdings Limited shareholders Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Shares used in the net loss per share computation: Weighted Average Number of Shares Outstanding, Basic and Diluted Basic and diluted Weighted average number of ordinary shares outstanding - basic and diluted Earnings Per Share, Basic and Diluted [Abstract] Net loss per share: Denominator: Basic and diluted Basic and diluted Basic and diluted loss per share Revenue from Related Parties Related Party Costs Cost from Related Parties Schedule of Business Acquisitions, by Acquisition [Table] Series A Convertible Preferred Shares [Member] Series A Convertible Preferred Shares [Member] Series A Convertible Preferred Shares [Member] Equity Components [Axis] Equity Component [Domain] Additional Paid-in Capital [Member] AOCI Attributable to Parent [Member] Retained Earnings [Member] Total Kingsoft Cloud Holdings Limited shareholdersdeficit equity [Member] Total Kingsoft Cloud Holdings Limited shareholders'(deficit) equity. Noncontrolling Interest [Member] Non-Controlling Interests Preferred Stock [Member] Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Share-based compensation (Note 16) Shares, Outstanding Balance (In shares) Balance (In shares) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other comprehensive income (loss) Stock Issued During Period, Shares, Conversion of Convertible Securities Conversion of Series A, Series B convertible preferred shares and Series C, Series D and Series D+ redeemable convertible preferred shares into ordinary shares (In shares) APIC, Share-based Payment Arrangement, ESPP, Increase for Cost Recognition Exercise and vesting of share-based awards (Note 16) Stock Issued During Period, Value, New Issues Issuance of ordinary shares Stock Issued During Period, Shares, Employee Stock Purchase Plans Exercise and vesting of share-based awards (Note 16) (In shares) Stock Repurchased During Period, Value Repurchase of ordinary shares Shares repurchased during the period value Stock Repurchased During Period, Shares Repurchase of ordinary shares (In shares) Shares repurchased during the period shares Stock Issued During Period, Value, Conversion of Convertible Securities Conversion of Series A, Series B convertible preferred shares and Series C, Series D and Series D+ redeemable convertible preferred shares into ordinary shares Stock Issued During Period, Shares, New Issues Issuance of ordinary shares (In shares) Stock shares issued during the period shares Adoption of ASC 326 Adoption of ASC 326. Stock Issued During Period, Shares, Acquisitions Business acquisition, Shares Stock Issued During Period, Value, Acquisitions Business acquisition Sale of Stock [Axis] Sale of Stock [Domain] IPO [Member] Follow on offering [Member] Follow on offering. Redeemable Convertible Preferred Stock [Member] Series B Converted Preferred Shares and Series C, D and D+ Redeemable Converted Preferred Shares [Member] Stock Issued During Period, Shares, Issued for Services Stock Issued During Period, Shares, Issued for Services Statement of Cash Flows [Abstract] Net Cash Provided by (Used in) Investing Activities [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES Proceed from Asset Related Government Grants Received Asset-related government grants received Proceed from asset-related government grants received. Payments to Acquire Investments Purchases of short-term investments Proceeds from Sale, Maturity and Collection of Investments Proceeds from maturities of short-term investments Payments to Acquire Equity Method Investments Acquisition of equity investments Cash Consideration Paid Payments to Acquire Intangible Assets Purchases of intangible assets Net Cash Provided by (Used in) Investing Activities Net cash (used in) generated from investing activities Net cash used in investing activities Net cash generated from (used in) investing activities Payments to Acquire Assets, Investing Activities Purchases of property and equipment Proceeds from Sale of Property, Plant, and Equipment Disposal of property and equipment Payments to Acquire Land Held-for-use Purchases of land use rights Payments to Fund Long-term Loans to Related Parties Loans to senior executives Proceeds from Sale of Equity Method Investments Disposal of equity investments Payments to Acquire Businesses, Net of Cash Acquired Acquisition of business, net of cash acquired 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 operating activities: Gain (Loss) on Investments Changes in fair value of equity investments