Cover [Abstract] Document Information [Table] Document Information [Line Items] Document Type Document Registration Statement Document Annual Report Document Period End Date Document Fiscal Year Focus Document Transition Report Document Shell Company Report Entity File Number Entity Registrant Name Title of 12(b) Security Trading Symbol Security Exchange Name Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Current Reporting Status Entity Voluntary Filers Entity Filer Category Entity Emerging Growth Company Entity Shell Company Entity Interactive Data Current Document Accounting Standard Amendment Flag Document Fiscal Period Focus Entity Central Index Key Current Fiscal Year End Date Entity Address, Address Line One Entity Address, City or Town Entity Address, Country Local Phone Number Contact Personnel Fax Number City Area Code Entity Address, Postal Zip Code Contact Personnel Name Entity Incorporation, State or Country Code No Trading Symbol Flag Entity Address, State or Province ICFR Auditor Attestation Flag Country Region Auditor Name Auditor Firm ID Auditor Location Entity Address, Address Line Two Entity Addresses, Address Type [Axis] Address Type [Domain] Business Contact [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] ADR [Member] American Depositary Shares [Member] Common Stock [Member] Ordinary shares[Member] Ordinary Shares Statement of Financial Position [Abstract] Assets [Abstract] ASSETS Long-term Investments Long-term investments Other Assets Other assets Assets Total assets Property, Plant and Equipment, Net Property and equipment, net Property, Plant and Equipment, Net Assets, Current [Abstract] Current Assets Accounts and Financing Receivable, after Allowance for Credit Loss, Current, Total Notes and accounts receivable, net Notes and accounts receivable, net Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Restricted Cash and Investments, Current Restricted assets-current Assets, Current Total current assets Disposal Group, Including Discontinued Operation, Assets, Current Noncurrent assets held for sale Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Total cash and cash equivalents Inventory Inventories Inventory, Net Inventories are stated at the lower of cost or market value. Inventories are recorded at standard cost and adjusted to the approximate weighted-average cost at the balance sheet date. Deferred Income Tax Assets, Net Deferred income tax assets, net Operating Lease, Right-of-Use Asset Operating lease assets Operating lease right of use assets Liabilities and Equity [Abstract] LIABILITIES AND SHAREHOLDERS' EQUITY Other Liabilities, Noncurrent Other long-term liabilities Liabilities, Current [Abstract] Current Liabilities Accounts Payable, Trade, Current Notes and accounts payable Accounts Payable and Other Accrued Liabilities, Current Accrued expenses and other current liabilities Accrued expenses and other current liabilities Liabilities, Current Total current liabilities Taxes Payable, Current Income tax payable Customer Refund Liability, Current Refund liabilities Liabilities and Equity Total liabilities and shareholders' equity Commitments and Contingencies Commitments and Contingencies (Note 18) Liabilities Total liabilities Stockholders' Equity Attributable to Parent [Abstract] Shareholders' Equity Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income (loss) Beginning balance, Accumulated other comprehensive income (loss) Ending balance, Accumulated other comprehensive income (loss) Additional Paid in Capital, Common Stock Additional paid-in capital Retained Earnings (Accumulated Deficit) Retained Earnings Common Stock, Value, Issued Ordinary Shares at US$0.01 par value per share Authorized: 500,000 thousand shares Issued and outstanding: 138,168 thousand shares in 2020 and 139,764 thousand shares in 2021 Stockholders' Equity Attributable to Parent Total shareholders' equity Beginning Balance Ending Balance Treasury Stock, Value Treasury Stock Common Stock, Shares, Outstanding Ordinary Shares, outstanding Ending Balance, shares Beginning Balance, shares Common Stock, Par or Stated Value Per Share Ordinary Shares, par value Common Stock, Shares Authorized Ordinary Shares, Authorized Common Stock, Shares, Issued Ordinary Shares, Issued Income Statement [Abstract] Cost of Goods and Services Sold COST OF SALES Earnings per American Depository Shares [Abstract] EARNINGS PER ADS (one ADS equals four ordinary shares): Earnings per American Depository Shares [Abstract] Earnings Per Share, ADS Basic Basic The amount of net income or loss for the period per each share of American Depository Receipts outstanding during the reporting period. Earnings Per Share, ADS Diluted Diluted The amount of net income or loss for the period per each share of American Depository Receipts and dilutive common stock equivalents outstanding during the reporting period. Earnings Per Share [Abstract] EARNINGS PER ORDINARY SHARE: Earnings Per Share, Diluted Diluted Earnings Per Share, Basic Basic Net Income (Loss) Attributable to Parent NET INCOME NET INCOME Net income Nonoperating Income (Expense) [Abstract] NON-OPERATING INCOME (EXPENSES) Nonoperating Income (Expense) Total non-operating income Interest Expense Interest expense Interest Income, Other Interest income Foreign Currency Transaction Gain (Loss), before Tax Foreign exchange gain, net Other Nonoperating Income (Expense) Other income (loss), net Gain on Sale of Investments Gain from disposal of short-term investments Gain (Loss) on Disposition of Stock in Subsidiary or Equity Method Investee Gain (loss) from disposal of subsidiary Gain (loss) from disposal of subsidiary Gain loss on disposal of subsidary Gain (Loss) on Sale of Other Investments Gain from disposal of long-term investments Gain from disposal of long-term investments Operating Expenses [Abstract] OPERATING EXPENSES Amortization of Intangible Assets Amortization of intangible assets Operating Expenses Total operating expenses Research and Development Expense Research and development Selling and Marketing Expense Sales and marketing Goodwill and Intangible Asset Impairment Impairment of goodwill and intangible assets General and Administrative Expense General and administrative Gross Profit GROSS PROFIT Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest INCOME BEFORE INCOME TAX Income before taxes Income Tax Expense (Benefit) INCOME TAX EXPENSE Income tax expense Revenue from Contract with Customer, Excluding Assessed Tax NET SALES Weighted Average American Depository Shares Outstanding [Abstract] WEIGHTED AVERAGE ADS OUTSTANDING Weighted Average American Depository Shares Outstanding [Abstract] Weighted Average Number of ADS Basic Shares Outstanding Basic (Thousands) Weighted Average Number of ADS Basic Shares Outstanding Weighted Average Number of ADS Diluted Shares Outstanding Diluted (Thousands) Weighted Average Number of ADS Diluted Shares Outstanding Operating Income (Loss) OPERATING INCOME Weighted Average Number of Shares Outstanding, Diluted [Abstract] WEIGHTED AVERAGE ORDINARY SHARES OUTSTANDING Weighted Average Number of Shares Outstanding, Basic Basic (Thousands) Weighted Average Number of Shares Outstanding, Diluted Diluted (Thousands) Statement of Comprehensive Income [Abstract] Comprehensive Income (Loss), Net of Tax, Attributable to Parent TOTAL COMPREHENSIVE INCOME Other Comprehensive Income (Loss), Net of Tax [Abstract] OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX EFFECT OF NIL Other Comprehensive Income (Loss), Net of Tax OTHER COMPREHENSIVE INCOME (LOSS) Other comprehensive income (loss) Current-period change, Accumulated other comprehensive income (loss) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Change in net foreign currency translation adjustments Current-period change, Foreign currency items Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Change in deferred pension gain (loss) Current-period change, Defined benefit pension plans Total recognized in other comprehensive loss (income) Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Treasury Stock [Member] Treasury Stock Retained Earnings [Member] Retained Earnings (accumulated deficit) AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Additional Paid-in Capital [Member] Additional Paid-in Capital Statement [Line Items] Statement [Line Items] Treasury Stock, Value, Acquired, Cost Method Share repurchase Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Issuance of ordinary shares upon exercise of restricted stock units, shares APIC, Share-based Payment Arrangement, Increase for Cost Recognition, Total Stock-based compensation expenses Treasury Stock, Retired, Cost Method, Amount Treasury stock retired Treasury Stock, Shares, Retired Treasury stock retired (Shares) Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Issuance of ordinary shares upon exercise of restricted stock units Dividends, Common Stock, Cash Dividends declared Common Stock, Dividends, Per Share, Declared Dividends declared, per share Dividend Per Share Dividend declared Statement of Cash Flows [Abstract] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, BEGINNING OF YEAR CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, END OF YEAR Total cash ,cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect NET INCREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents EFFECT OF EXCHANGE RATE CHANGES Net Cash Provided by (Used in) Financing Activities [Abstract] CASH FLOWS FROM FINANCING ACTIVITIES Payments of Dividends Dividends paid Payments for Repurchase of Common Stock Share repurchase Proceeds from Bank Debt Proceeds from bank loan Net Cash Provided by (Used in) Financing Activities Net cash used in financing activities Repayments of Bank Debt Repayments of bank loan Repayments of bank debt Net Cash Provided by (Used in) Investing Activities [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES Payments to Acquire Long-term Investments Purchase of long-term investment Payments to Acquire Property, Plant, and Equipment Purchase of property and equipment Proceeds from Divestiture of Interest in Subsidiaries and Affiliates Proceeds from sale of subsidiary Proceeds from sale of subsidiary Proceeds from Sale of Long-term Investments Proceeds from sale of long-term investment Net Cash Provided by (Used in) Investing Activities Net cash provided by (used in) investing activities 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 income to net cash provided by operating activities: Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Accounts and Notes Receivable Notes and accounts receivable Increase (Decrease) in Accounts Payable and Accrued Liabilities Accrued expenses and other current liabilities Increase (Decrease) in Income Taxes Income tax payable Increase (Decrease) in Inventories Inventories Increase (Decrease) In Notes Payable and Accounts Payable, Trade Notes and accounts payable Increase (Decrease) In Notes Payable and Accounts Payable, Trade Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Increase Decrease In Refund Liabilities Refund liabilities Increase decrease in refund liabilities. Increase Decrease In Short Term Investments Short-term investments Increase Decrease In Short Term Investments Increase (Decrease) in Other Operating Liabilities Other liabilities Deferred Income Tax Expense (Benefit) Deferred income taxes Deferred Gain (Loss) on Sale of Investments Gain from disposal of short-term investments Depreciation, Depletion and Amortization Depreciation and amortization Gain (Loss) on Disposition of Property Plant Equipment Loss on disposal of property and equipment Share-based Payment Arrangement, Noncash Expense, Total Stock-based compensation Share-based compensation expense Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income Net Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Supplemental Cash Flow Elements [Abstract] SUPPLEMENTAL INFORMATION Income Taxes Paid Income taxes paid Disposal of FCI [Abstract] Disposal of FCI Disposal of FCI. Noncash or Part Noncash Divestiture, Amount of Consideration Received Total consideration Other Current Asset Disposed Other current assets Other current asset disposed Cash And Restricted Cash Disposed Cash and restricted cash disposed Cash and restricted cash disposed