3.23.1 html 259 408 1 false 86 0 false 7 false false R1.htm 000 - Document - Document And Entity Information Sheet http://www.beyondspringpharma.com/20221231/role/statement-document-and-entity-information Document And Entity Information Cover 1 false false R2.htm 001 - Statement - Consolidated Balance Sheets Sheet http://www.beyondspringpharma.com/20221231/role/statement-consolidated-balance-sheets- Consolidated Balance Sheets Statements 2 false false R3.htm 002 - Statement - Consolidated Balance Sheets (Parentheticals) Sheet http://www.beyondspringpharma.com/20221231/role/statement-consolidated-balance-sheets-parentheticals Consolidated Balance Sheets (Parentheticals) Statements 3 false false R4.htm 003 - Statement - Consolidated Statements of Comprehensive Loss Sheet http://www.beyondspringpharma.com/20221231/role/statement-consolidated-statements-of-comprehensive-loss- Consolidated Statements of Comprehensive Loss Statements 4 false false R5.htm 004 - Statement - Consolidated Statements of Shareholders' Equity (Deficit) Sheet http://www.beyondspringpharma.com/20221231/role/statement-consolidated-statements-of-shareholders-equity-deficit Consolidated Statements of Shareholders' Equity (Deficit) Statements 5 false false R6.htm 005 - Statement - Consolidated Statements of Cash Flows Sheet http://www.beyondspringpharma.com/20221231/role/statement-consolidated-statements-of-cash-flows- Consolidated Statements of Cash Flows Statements 6 false false R7.htm 006 - Disclosure - Note 1 - Nature of the Business Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-1-nature-of-the-business Note 1 - Nature of the Business Notes 7 false false R8.htm 007 - Disclosure - Note 2 - Summary of Significant Accounting Policies Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies Note 2 - Summary of Significant Accounting Policies Notes 8 false false R9.htm 008 - Disclosure - Note 3 - Short-term Investments Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-3-shortterm-investments Note 3 - Short-term Investments Notes 9 false false R10.htm 009 - Disclosure - Note 4 - Collaboration Revenue Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-4-collaboration-revenue Note 4 - Collaboration Revenue Notes 10 false false R11.htm 010 - Disclosure - Note 5 - Property and Equipment, Net Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-5-property-and-equipment-net Note 5 - Property and Equipment, Net Notes 11 false false R12.htm 011 - Disclosure - Note 6 - Long-term Loans Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-6-longterm-loans Note 6 - Long-term Loans Notes 12 false false R13.htm 012 - Disclosure - Note 7 - Related Party Transactions Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-7-related-party-transactions Note 7 - Related Party Transactions Notes 13 false false R14.htm 013 - Disclosure - Note 8 - Income Taxes Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes Note 8 - Income Taxes Notes 14 false false R15.htm 014 - Disclosure - Note 9 - Net Loss Per Share Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-9-net-loss-per-share Note 9 - Net Loss Per Share Notes 15 false false R16.htm 015 - Disclosure - Note 10 - Share-based Compensation Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation Note 10 - Share-based Compensation Notes 16 false false R17.htm 016 - Disclosure - Note 11 - Employee Defined Contribution Plan Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-11-employee-defined-contribution-plan Note 11 - Employee Defined Contribution Plan Notes 17 false false R18.htm 017 - Disclosure - Note 12 - Restricted Net Assets Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-12-restricted-net-assets Note 12 - Restricted Net Assets Notes 18 false false R19.htm 018 - Disclosure - Note 13 - Leases Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-13-leases Note 13 - Leases Notes 19 false false R20.htm 019 - Disclosure - Note 14 - Supplemental Balance Sheet Information Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-14-supplemental-balance-sheet-information Note 14 - Supplemental Balance Sheet Information Notes 20 false false R21.htm 020 - Disclosure - Note 15 - Contingently Redeemable Noncontrolling Interests Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-15-contingently-redeemable-noncontrolling-interests- Note 15 - Contingently Redeemable Noncontrolling Interests Notes 21 false false R22.htm 021 - Disclosure - Note 16 - Forward Contract Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-16-forward-contract Note 16 - Forward Contract Notes 22 false false R23.htm 022 - Disclosure - Note 17 - Accumulated Other Comprehensive Income (Loss) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-17-accumulated-other-comprehensive-income-loss Note 17 - Accumulated Other Comprehensive Income (Loss) Notes 23 false false R24.htm 023 - Disclosure - Note 18 - Commitments and Contingencies Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-18-commitments-and-contingencies Note 18 - Commitments and Contingencies Notes 24 false false R25.htm 024 - Disclosure - Note 19 - Segment Reporting and Geographic Information Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information Note 19 - Segment Reporting and Geographic Information Notes 25 false false R26.htm 025 - Disclosure - Note 20 - Fair Value Measurements Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-20-fair-value-measurements Note 20 - Fair Value Measurements Notes 26 false false R27.htm 026 - Disclosure - Note 21 - Subsequent Events Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-21-subsequent-events Note 21 - Subsequent Events Notes 27 false false R28.htm 027 - Disclosure - Significant Accounting Policies (Policies) Sheet http://www.beyondspringpharma.com/20221231/role/statement-significant-accounting-policies-policies Significant Accounting Policies (Policies) Policies http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies 28 false false R29.htm 028 - Disclosure - Note 1 - Nature of the Business (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-1-nature-of-the-business-tables Note 1 - Nature of the Business (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-1-nature-of-the-business 29 false false R30.htm 029 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies-tables Note 2 - Summary of Significant Accounting Policies (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies 30 false false R31.htm 030 - Disclosure - Note 3 - Short-term Investments (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-3-shortterm-investments-tables Note 3 - Short-term Investments (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-3-shortterm-investments 31 false false R32.htm 031 - Disclosure - Note 4 - Collaboration Revenue (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-4-collaboration-revenue-tables Note 4 - Collaboration Revenue (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-4-collaboration-revenue 32 false false R33.htm 032 - Disclosure - Note 5 - Property and Equipment, Net (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-5-property-and-equipment-net-tables Note 5 - Property and Equipment, Net (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-5-property-and-equipment-net 33 false false R34.htm 033 - Disclosure - Note 8 - Income Taxes (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-tables Note 8 - Income Taxes (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes 34 false false R35.htm 034 - Disclosure - Note 9 - Net Loss Per Share (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-9-net-loss-per-share-tables Note 9 - Net Loss Per Share (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-9-net-loss-per-share 35 false false R36.htm 035 - Disclosure - Note 10 - Share-based Compensation (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-tables Note 10 - Share-based Compensation (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation 36 false false R37.htm 036 - Disclosure - Note 13 - Leases (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-13-leases-tables Note 13 - Leases (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-13-leases 37 false false R38.htm 037 - Disclosure - Note 14 - Supplemental Balance Sheet Information (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-14-supplemental-balance-sheet-information-tables Note 14 - Supplemental Balance Sheet Information (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-14-supplemental-balance-sheet-information 38 false false R39.htm 038 - Disclosure - Note 15 - Contingently Redeemable Noncontrolling Interests (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-15-contingently-redeemable-noncontrolling-interests-tables Note 15 - Contingently Redeemable Noncontrolling Interests (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-15-contingently-redeemable-noncontrolling-interests- 39 false false R40.htm 039 - Disclosure - Note 17 - Accumulated Other Comprehensive Income (Loss) (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-17-accumulated-other-comprehensive-income-loss-tables Note 17 - Accumulated Other Comprehensive Income (Loss) (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-17-accumulated-other-comprehensive-income-loss 40 false false R41.htm 040 - Disclosure - Note 19 - Segment Reporting and Geographic Information (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information-tables Note 19 - Segment Reporting and Geographic Information (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information 41 false false R42.htm 041 - Disclosure - Note 20 - Fair Value Measurements (Tables) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-20-fair-value-measurements-tables Note 20 - Fair Value Measurements (Tables) Tables http://www.beyondspringpharma.com/20221231/role/statement-note-20-fair-value-measurements 42 false false R43.htm 042 - Disclosure - Note 1 - Nature of the Business (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-1-nature-of-the-business-details-textual Note 1 - Nature of the Business (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-1-nature-of-the-business-tables 43 false false R44.htm 043 - Disclosure - Note 1 - Nature of the Business - Schedule of Subsidiaries (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-1-nature-of-the-business-schedule-of-subsidiaries-details Note 1 - Nature of the Business - Schedule of Subsidiaries (Details) Details 44 false false R45.htm 044 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies-details-textual Note 2 - Summary of Significant Accounting Policies (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies-tables 45 false false R46.htm 045 - Disclosure - Note 2 - Summary of Significant Accounting Policies - Useful Life of Property, Plant, and Equipment (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-2-summary-of-significant-accounting-policies-useful-life-of-property-plant-and-equipment-details Note 2 - Summary of Significant Accounting Policies - Useful Life of Property, Plant, and Equipment (Details) Details 46 false false R47.htm 046 - Disclosure - Note 3 - Short-term Investments - Short-term Investments (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-3-shortterm-investments-shortterm-investments-details Note 3 - Short-term Investments - Short-term Investments (Details) Details 47 false false R48.htm 047 - Disclosure - Note 4 - Collaboration Revenue (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-4-collaboration-revenue-details-textual Note 4 - Collaboration Revenue (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-4-collaboration-revenue-tables 48 false false R49.htm 048 - Disclosure - Note 4 - Collaboration Revenue - Schedule of Collaboration Revenue (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-4-collaboration-revenue-schedule-of-collaboration-revenue-details Note 4 - Collaboration Revenue - Schedule of Collaboration Revenue (Details) Details 49 false false R50.htm 049 - Disclosure - Note 5 - Property and Equipment, Net (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-5-property-and-equipment-net-details-textual Note 5 - Property and Equipment, Net (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-5-property-and-equipment-net-tables 50 false false R51.htm 050 - Disclosure - Note 5 - Property and Equipment, Net - Schedule of Property and Equipment (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-5-property-and-equipment-net-schedule-of-property-and-equipment-details Note 5 - Property and Equipment, Net - Schedule of Property and Equipment (Details) Details 51 false false R52.htm 051 - Disclosure - Note 6 - Long-term Loans (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-6-longterm-loans-details-textual Note 6 - Long-term Loans (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-6-longterm-loans 52 false false R53.htm 052 - Disclosure - Note 7 - Related Party Transactions (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-7-related-party-transactions-details-textual Note 7 - Related Party Transactions (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-7-related-party-transactions 53 false false R54.htm 053 - Disclosure - Note 8 - Income Taxes (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-details-textual Note 8 - Income Taxes (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-tables 54 false false R55.htm 054 - Disclosure - Note 8 - Income Taxes - Components of Losses Before Income Taxes (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement--note-8-income-taxes-components-of-losses-before-income-taxes-details Note 8 - Income Taxes - Components of Losses Before Income Taxes (Details) Details 55 false false R56.htm 055 - Disclosure - Note 8 - Income Taxes - Provision for Income Expense (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-provision-for-income-expense-details Note 8 - Income Taxes - Provision for Income Expense (Details) Details 56 false false R57.htm 056 - Disclosure - Note 8 - Income Taxes - Reconciliation of Income Tax Expenses (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-reconciliation-of-income-tax-expenses-details Note 8 - Income Taxes - Reconciliation of Income Tax Expenses (Details) Details 57 false false R58.htm 057 - Disclosure - Note 8 - Income Taxes - Deferred Tax Assets (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-deferred-tax-assets-details Note 8 - Income Taxes - Deferred Tax Assets (Details) Details 58 false false R59.htm 058 - Disclosure - Note 8 - Income Taxes - Unrecognized Tax Benefits (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-8-income-taxes-unrecognized-tax-benefits-details Note 8 - Income Taxes - Unrecognized Tax Benefits (Details) Details 59 false false R60.htm 059 - Disclosure - Note 9 - Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-9-net-loss-per-share-basic-and-diluted-net-loss-per-share-details Note 9 - Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) Details 60 false false R61.htm 060 - Disclosure - Note 10 - Share-based Compensation (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-details-textual Note 10 - Share-based Compensation (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-tables 61 false false R62.htm 061 - Disclosure - Note 10 - Share-based Compensation - Restricted Share Activities (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-restricted-share-activities-details Note 10 - Share-based Compensation - Restricted Share Activities (Details) Details 62 false false R63.htm 062 - Disclosure - Note 10 - Share-based Compensation - Options Activities (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-options-activities-details Note 10 - Share-based Compensation - Options Activities (Details) Details 63 false false R64.htm 063 - Disclosure - Note 10 - Share-based Compensation - Fair Value Assumptions (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-fair-value-assumptions-details Note 10 - Share-based Compensation - Fair Value Assumptions (Details) Details 64 false false R65.htm 064 - Disclosure - Note 10 - Share-based Compensation - Share-based Compensation Expense (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-10-sharebased-compensation-sharebased-compensation-expense-details Note 10 - Share-based Compensation - Share-based Compensation Expense (Details) Details 65 false false R66.htm 065 - Disclosure - Note 11 - Employee Defined Contribution Plan (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-11-employee-defined-contribution-plan-details-textual Note 11 - Employee Defined Contribution Plan (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-11-employee-defined-contribution-plan 66 false false R67.htm 066 - Disclosure - Note 12 - Restricted Net Assets (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-12-restricted-net-assets-details-textual Note 12 - Restricted Net Assets (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-12-restricted-net-assets 67 false false R68.htm 067 - Disclosure - Note 13 - Leases (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-13-leases-details-textual Note 13 - Leases (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-13-leases-tables 68 false false R69.htm 068 - Disclosure - Note 13 - Lease - Maturities of Lease Liabilities (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-13-lease-maturities-of-lease-liabilities-details Note 13 - Lease - Maturities of Lease Liabilities (Details) Details 69 false false R70.htm 069 - Disclosure - Note 13 - Lease - Operating Lease Disclosure (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-13-lease-operating-lease-disclosure-details Note 13 - Lease - Operating Lease Disclosure (Details) Details 70 false false R71.htm 070 - Disclosure - Note 14 - Supplemental Balance Sheet Information - Other Noncurrent Assets (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-14-supplemental-balance-sheet-information-other-noncurrent-assets-details Note 14 - Supplemental Balance Sheet Information - Other Noncurrent Assets (Details) Details 71 false false R72.htm 071 - Disclosure - Note 14 - Supplemental Balance Sheet Information - Other Current Liabilities (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-14-supplemental-balance-sheet-information-other-current-liabilities-details Note 14 - Supplemental Balance Sheet Information - Other Current Liabilities (Details) Details 72 false false R73.htm 072 - Disclosure - Note 14 - Supplemental Balance Sheet Information - Other Noncurrent Liabilities (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-14-supplemental-balance-sheet-information-other-noncurrent-liabilities-details Note 14 - Supplemental Balance Sheet Information - Other Noncurrent Liabilities (Details) Details 73 false false R74.htm 073 - Disclosure - Note 15 - Contingently Redeemable Noncontrolling Interests (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-15-contingently-redeemable-noncontrolling-interests-details-textual Note 15 - Contingently Redeemable Noncontrolling Interests (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-15-contingently-redeemable-noncontrolling-interests-tables 74 false false R75.htm 074 - Disclosure - Note 15 - Contingently Redeemable Noncontrolling Interests - Redeemable Noncontrolling Interests, Net of Issuance Costs (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-15-contingently-redeemable-noncontrolling-interests-redeemable-noncontrolling-interests-net-of-issuance-costs-details Note 15 - Contingently Redeemable Noncontrolling Interests - Redeemable Noncontrolling Interests, Net of Issuance Costs (Details) Details 75 false false R76.htm 075 - Disclosure - Note 16 - Forward Contract (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-16-forward-contract-details-textual Note 16 - Forward Contract (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-16-forward-contract 76 false false R77.htm 076 - Disclosure - Note 17 - Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Loss) (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-17-accumulated-other-comprehensive-income-loss-accumulated-other-comprehensive-income-loss-details Note 17 - Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Loss) (Details) Details http://www.beyondspringpharma.com/20221231/role/statement-note-17-accumulated-other-comprehensive-income-loss-tables 77 false false R78.htm 077 - Disclosure - Note 19 - Segment Reporting and Geographic Information (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information-details-textual Note 19 - Segment Reporting and Geographic Information (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information-tables 78 false false R79.htm 078 - Disclosure - Note 19 - Segment Reporting and Geographic Information - Operating Information by Segment (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information-operating-information-by-segment-details Note 19 - Segment Reporting and Geographic Information - Operating Information by Segment (Details) Details 79 false false R80.htm 079 - Disclosure - Note 19 - Segment Reporting and Geographic Information - Long Lived Assets by Geographic Area (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-19-segment-reporting-and-geographic-information-long-lived-assets-by-geographic-area-details Note 19 - Segment Reporting and Geographic Information - Long Lived Assets by Geographic Area (Details) Details 80 false false R81.htm 080 - Disclosure - Note 20 - Fair Value Measurements - Recurring Fair Value Measurement (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-20-fair-value-measurements-recurring-fair-value-measurement-details Note 20 - Fair Value Measurements - Recurring Fair Value Measurement (Details) Details 81 false false R82.htm 081 - Disclosure - Note 20 - Fair Value Measurements - Significant Unobservable Inputs on Fair Value (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-20-fair-value-measurements-significant-unobservable-inputs-on-fair-value-details Note 20 - Fair Value Measurements - Significant Unobservable Inputs on Fair Value (Details) Details 82 false false R83.htm 082 - Disclosure - Note 20 - Fair Value Measurements - Derivatives Measured on Recurring Basis, Unobservable Input Reconciliation (Details) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-20-fair-value-measurements-derivatives-measured-on-recurring-basis-unobservable-input-reconciliation-details Note 20 - Fair Value Measurements - Derivatives Measured on Recurring Basis, Unobservable Input Reconciliation (Details) Details 83 false false R84.htm 083 - Disclosure - Note 21 - Subsequent Events (Details Textual) Sheet http://www.beyondspringpharma.com/20221231/role/statement-note-21-subsequent-events-details-textual Note 21 - Subsequent Events (Details Textual) Details http://www.beyondspringpharma.com/20221231/role/statement-note-21-subsequent-events 84 false false All Reports Book All Reports [dq-0547-EntityAddressCountry-Missing] Submission type 20-F should have a non-empty value for EntityAddressCountry in the Required Context. bysi20221230_20f.htm [ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 44 fact(s) appearing in ix:hidden were eligible for transformation: bysi:CollaborationAgreementMaximumCommercialMilestonesToBeReceived, bysi:CollaborationAgreementMaximumRegulatoryDevelopmentMilestonesToBeReceived, bysi:CollaborationAgreementUpfrontCashPayment, bysi:EffectiveIncomeTaxRateReconciliationAtPreferentialIncomeTaxRateDurationForeign, bysi:InvestmentAgreementAmount, bysi:RestrictedNetAssets, dei:CurrentFiscalYearEndDate, dei:EntityRegistrantName, us-gaap:AllowanceForDoubtfulAccountsReceivable, us-gaap:CommonStockParOrStatedValuePerShare, us-gaap:CommonStockSharesAuthorized, us-gaap:CommonStockSharesIssued, us-gaap:CommonStockSharesOutstanding, us-gaap:DebtInstrumentTerm, us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLoss, us-gaap:ImpairmentOfLongLivedAssetsToBeDisposedOf, us-gaap:LongTermDebt, us-gaap:NumberOfReportableSegments, us-gaap:ProceedsFromMinorityShareholders, us-gaap:ProceedsFromShortTermDebt, us-gaap:PropertyPlantAndEquipmentUsefulLife, us-gaap:RepaymentsOfLongTermDebt, us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax, us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1, us-gaap:ShortTermLeaseCost, us-gaap:TemporaryEquityStockIssuedDuringPeriodValueNewIssues, us-gaap:UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense - bysi20221230_20f.htm 8, 10, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 52, 53, 54, 55, 56, 57, 58 bysi20221230_20f.htm bysi-20221231.xsd bysi-20221231_cal.xml bysi-20221231_def.xml bysi-20221231_lab.xml bysi-20221231_pre.xml ex_500853.htm ex_500854.htm ex_500856.htm ex_500857.htm ex_500858.htm ex_500859.htm ex_500860.htm ex_500861.htm ex_500862.htm ex_500895.htm ex_500908.htm p118organizationalstructurec.jpg p83ourpipelinecopy.jpg http://fasb.org/us-gaap/2022 http://xbrl.sec.gov/dei/2022 true true