Summary of Significant Accounting Policies [Abstract] Accrued expenses Accrued Liabilities, Current Additional Paid-in Capital [Member] Additional paid-in capital Offering costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Adjustments to reconcile net loss to net cash used in operating activities: Investments held in Trust Account [Abstract] Assets, Fair Value Disclosure [Abstract] Assets: Assets [Abstract] Total assets Assets Total current assets Assets, Current Current assets: Proceeds deposited into trust account Investments held in Trust Account Assets Held-in-trust, Noncurrent Basis of Presentation Summary of Significant Accounting Policies Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] Implied equity value Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Cash and Cash Equivalents [Abstract] Net change in cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Cash - end of the period Cash - beginning of the period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash Cash at bank Cash and Cash Equivalents Cash equivalents Cash Equivalents, at Carrying Value Supplemental disclosure of noncash investing and financing activities: Class of Warrant or Right [Domain] Class of Warrant or Right [Axis] Class of Stock [Line Items] Class of Stock [Domain] Commitments and Contingencies (Note 5) Commitments & Contingencies Commitments and Contingencies Disclosure [Text Block] Commitments & Contingencies [Abstract] Class B Ordinary Shares [Member] Class A Ordinary Shares Subject to Redemption [Member] Common Stock Subject to Mandatory Redemption [Member] Ordinary Shares [Member] Class A Ordinary Shares [Member] Ordinary shares, par value (in dollars per share) Ordinary shares, shares issued (in shares) Ordinary shares, shares authorized (in shares) Ordinary shares, shares outstanding (in shares) Common stock Common Stock, Value, Issued Concentration of Credit Risk Conversion value Conversion price (in dollars per share) Offering Costs Associated with the Initial Public Offering Deferred Charges, Policy [Policy Text Block] Deferred offering costs associated with initial public offering Basic and diluted net income (loss) per share (in dollars per share) Net Income (Loss) Per Ordinary Share Earnings Per Share, Policy [Policy Text Block] Net Income (Loss) Per Share [Abstract] Equity Component [Domain] Shareholders' Equity [Abstract] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Transfers from Level 1 to Level 2 Transfers from Level 2 to Level 1 Asset Class [Domain] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Transfers in into Level 3 Recurring [Member] Fair Value Measurements [Abstract] Transfers out of Level 3 Asset Class [Axis] Measurement Frequency [Domain] Measurement Frequency [Axis] Fair Value, Recurring and Nonrecurring [Table] Fair Value Measurements Assets Measured on Recurring Basis Quoted Prices in Active Markets (Level 1) [Member] Significant Other Observable Inputs (Level 2) [Member] Significant Other Unobservable Inputs (Level 3) [Member] Net gain, dividends and interest on investments held in Trust Account Net income on investments Net gain, dividends and interest on investments held in Trust Account General and administrative expenses Income Taxes [Abstract] Income Tax Disclosure [Abstract] STATEMENT OF OPERATIONS [Abstract] Income Taxes Prepaid expenses Increase (Decrease) in Prepaid Expenses, Other Accrued expenses Increase (Decrease) in Accrued Liabilities Changes in operating assets and liabilities: Increase (Decrease) in Stockholders' Equity [Roll Forward] Investment Securities Held in Trust Account Investment, Policy [Policy Text Block] Investments held in Trust Account Sponsor [Member] Sponsor [Member] Initial Public Offering [Member] IPO [Member] Total Liabilities and Shareholders' Equity Liabilities and Equity Liabilities and Shareholders' Equity: Liabilities and Equity [Abstract] Total liabilities Liabilities Total current liabilities Liabilities, Current Current liabilities: Cash Equivalents - Money Market Funds [Member] Money Market Funds [Member] Net asset value investments (in dollars per share) Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Net loss Net loss Net Income (Loss) Attributable to Parent Cash Flows from Investing Activities: Cash Flows from Operating Activities: Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Cash Flows from Financing Activities: Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Other income: Working capital loan outstanding amount Borrowings outstanding Over-Allotment Option [Member] Loss from operations Operating Income (Loss) Loss from Operations Description of Organization and Business Operations Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Description of Organization and Business Operations [Abstract] Common stock subject to possible redemption [Abstract] Offering costs paid Payments of Stock Issuance Costs Underwriting expense Preference shares, shares issued (in shares) Preference shares, $0.0001 par value; 1,000,000 shares authorized; none issued and outstanding Preference shares, shares outstanding (in shares) Preference shares, par value (in dollars per share) Preference shares, shares authorized (in shares) Prepaid expenses Private Placement [Member] Gross proceeds from shares issued Proceeds from issuance of common stock Proceeds received from initial public offering, gross Gross proceeds from initial public offering Proceeds received from private placement Gross proceeds from private placement Sponsor and Initial Public Offering [Abstract] Proceeds from Issuance or Sale of Equity [Abstract] Proceeds from note payable to related party Loan proceeds Related Party Transactions [Abstract] Related Party [Domain] Related Party Transaction [Line Items] Related Party Loans [Abstract] Related Party [Axis] General and administrative expenses paid by related party under note payable Related Party Transaction [Axis] Related party transaction Related Party Transaction [Domain] Related Party Transactions Repayment of note payable to related party Repayment of debt to related party Accumulated deficit Accumulated Deficit [Member] Sale of Stock [Domain] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Stock by Class [Table] Share price (in dollars per share) Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Share price (in dollars per share) Shares Issued, Price Per Share BALANCE SHEET [Abstract] Statement [Table] Statement [Line Items] STATEMENT OF CASH FLOWS [Abstract] Equity Components [Axis] Class of Stock [Axis] STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY [Abstract] Number of shares issued (in shares) Stock Issued During Period, Shares, Acquisitions Issuance of Class B ordinary shares to Sponsor (in shares) Shares issued (in shares) Issuance of Class B ordinary shares to Sponsor Shareholders' Equity Beginning balance Ending balance Total shareholders' equity Stockholders' Equity Attributable to Parent Shareholders' Equity: Stockholders' Equity [Abstract] Subsequent Event Type [Axis] Subsequent Events Subsequent Events [Text Block] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Events [Abstract] Sale of Stock [Axis] Subsidiary, Sale of Stock [Line Items] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Ordinary shares, par value (in dollars per share) Temporary Equity, Par or Stated Value Per Share Ordinary shares subject to possible redemption, redemption price (in dollars per share) Temporary Equity [Line Items] Ordinary shares subject to possible redemption (in shares) Temporary Equity, Shares Outstanding Class A ordinary shares, $0.0001 par value; 14,023,673 shares subject to possible redemption at $10.00 per share Temporary Equity, Carrying Amount, Attributable to Parent Temporary Equity, by Class of Stock [Table] Accrued interest and penalties Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Unrecognized tax benefits Unrecognized Tax Benefits Use of Estimates US Treasury Securities [Member] Basic and diluted weighted average shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Independent Director [Member] Director [Member] Maximum [Member] Minimum [Member] Statistical Measurement [Axis] Statistical Measurement [Domain] Cover page. Amendment Flag Current Fiscal Year End Date Document Period End Date Entity Listings [Table] Entity Address, State or Province Entity Listings [Line Items] Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Registrant Name Entity Central Index Key Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Document Type Entity Interactive Data Current Entity Shell Company Entity Emerging Growth Company Entity Ex Transition Period Entity Small Business Related Proposed Transactions [Abstract] Proposed Nautilus Business Combination and related Proposed Transactions [Abstract] Represents the acquiree in a business combination. Nautilus Biotechnology, Inc. [Member] Nautilus Biotechnology, Inc. [Member] Refers to the basis of equity conversion in a business combination from which a specified number of equity shares of the acquiring entity are converted into equity shares of the acquired entity upon completion of the business combination. Business Combination, Share Conversion Ratio Business combination share conversion (in shares) The amount of difference between current assets and liabilities. Working Capital Working capital Liquidity and Capital Resources [Abstract] Liquidity and Capital Resources [Abstract] Initial Public Offering of Units [Abstract] Initial Public Offering [Abstract] Deferred underwriting discount fee per unit payable to underwriters in the event the Company completes a Business Combination, subject to terms of the underwriting agreement. Underwriting Discount Fee Deferred Deferred underwriting discount (in dollars per share) Underwriting discount fee per unit paid to underwriters. Underwriting Discount Fee Underwriting discount (in dollars per share) Period of underwriter to purchase options. Sale of Stock Underwriter, Option Term Sale of stock underwriter option term Underwriting Agreement [Abstract] Underwriting Agreement [Abstract] Ratio applied to the conversion of stock, for example but not limited to, one share converted to two or two shares converted to one. Stock Conversion Ratio Stock conversion basis at time of business combination Number of shares of common stock and temporary equity outstanding. Common stock represent the ownership interest in a corporation. Common Stock and Temporary Equity, Shares, Outstanding Ordinary shares including common stock subject to possible redemption shares, Outstanding The stock conversion percentage threshold equal to the sum of the total number of all shares of common stock outstanding upon the completion of the Initial Public Offering plus all shares of Class A common stock and equity-linked securities issued or deemed issued in connection with the initial Business Combination (excluding any shares or equity-linked securities issued, or to be issued, to any seller in the initial Business Combination and any private placement-equivalent warrants issued to the Sponsor or its affiliates upon conversion of loans made to the Company). Stock Conversion Percentage Threshold Stock conversion percentage threshold Classification of common stock representing ownership interest in a corporation. Common Class A and Common Class B [Member] Class A Ordinary Shares not Subject to Redemption and Class B Ordinary Shares [Member] Threshold period after the initial Business Combination for the common stock price to exceed the threshold price per share, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Threshold Period after Initial Business Combination Threshold period after initial Business Combination The ownership interest percentage threshold for the Company's issued and outstanding shares after the Initial Public Offering for the Founder Shares. Ownership Interest Percentage Threshold Ownership interest, as converted percentage Number of common stock shares subject to forfeiture in the event of the over-allotment option was not exercised by the underwriters. Common Stock, Shares, Subject to Forfeiture Shares subject to forfeiture (in shares) Private Placement Warrants [Abstract] Private Placement Warrants [Abstract] The period of time after the completion of initial business combination that initial shareholders are not permitted to transfer, assign or sell any of their held Founder Shares. Period of Restriction for Founder Shares for Initial Shareholders Period to not transfer, assign or sell Founder Shares Threshold period of specified trading days that common stock price exceeds threshold price per share, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Trading Days Threshold Trading day threshold period Number of trading days for common stock price to exceed threshold, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Number of Trading Days Number of trading days Founder Shares [Abstract] Founder Shares [Abstract] Working capital loans to finance transaction costs in connection with a Business Combination. Working Capital Loans [Member] ARYA Sciences Holdings II (Sponsor), an affiliate of the Sponsor, or certain of the Company's officers and directors. Sponsor Affiliate of Sponsor or Certain Company Officers and Directors [Member] Sponsor Affiliate of Sponsor or Certain Company Officers and Directors [Member] Amount of the periodic payment due to related party during the financial reporting period. Related Party Transaction, Periodic Payment Amount Monthly fee Administrative Support Agreement [Abstract] Administrative Support Agreement [Abstract] Loan of up to $300,000 to cover expenses related to the Initial Public Offering pursuant to a promissory note (Note). The Note was non-interest bearing and payable on the earlier of June 30, 2018 or the completion of the Initial Public Offering. Promissory Note to Cover Expenses Related to Initial Public Offering [Member] Promissory Note [Member] An agreement whereby, on the effective date of the registration statement on Form S-1 related to the Initial Public Offering through the earlier of consummation of the initial Business Combination and the Company's liquidation, the Company will pay a monthly fee for office space, utilities and secretarial and administrative support. Administrative Support Agreement [Member] Purchase arrangement in which the entity has agreed to sell certain amount of shares. Forward Purchase Arrangement [Member] Carrying value as of the balance sheet date of outstanding underwriting commissions payable initially due after one year or beyond the operating cycle if longer, excluding current portion. Deferred Underwriting Commissions Deferred underwriting commissions Security that gives the holder the right to purchase Private Placement Shares. Private Placement Units [Member] Private Placement Units [Member] Units sold in a public offering that consist of Class A common stock. Public Shares [Member] Public Shares [Member] Number of new units issued during the period. Each unit consists of one share of Class A common stock. Units Issued During Period, Shares, New Issues Units issued (in shares) Interest received on the Trust Account that can be used to pay dissolution expenses if a Business Combination is not completed with the Combination Period. Interest on Trust Account to be held to pay dissolution expenses Interest from Trust Account that can be held to pay dissolution expenses Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Organization and Business Operations [Line Items] Disclosure of information about the Company's organization and business operations. Organization and Business Operations [Table] Assets held in Trust Account [Abstract] Trust Account [Abstract] Disclosure of accounting policy for shares subject to possible redemption. Shares Subject to Possible Redemption [Policy Text Block] Class A Ordinary Shares Subject to Possible Redemption Investment Securities Held In Trust Account [Abstract] The entire disclosure for the initial public offering of the Company's common stock. Initial Public Offering [Text Block] Initial Public Offering Initial Public Offering [Abstract] Carrying value as of the balance sheet date of outstanding underwriting fee payable initially due after one year or beyond the operating cycle if longer, excluding current portion. Deferred Underwriting Fee Payable Non Current Deferred underwriting commissions Deferred underwriting commissions The number of unit issued to Sponsor in Private Placement. Sale of Units to Sponsor in Private Placement Shares Sale of private placement units to Sponsor in private placement (in shares) Equity impact of the value of shares subject to possible redemption reclassified to temporary equity. Reclassifications Of Permanent To Temporary Equity Value Shares subject to possible redemption Number of new shares issued during the period in initial public offering. Shares Issued in Initial Public Offering During Period Shares New Issues Sale of units in initial public offering, gross (in shares) The value of new stock issued during the period in initial public offering. Shares Issued in Initial Public Offering During Period Value New Issues Sale of units in initial public offering, gross Equity impact of the value of units issued to sponsor In private placement during the period. Sale of Units to Sponsor in Private Placement, Value Sale of private placement units to Sponsor in private placement Number of shares subject to possible redemption reclassified to temporary equity. Reclassifications of Permanent to Temporary Equity, Shares Shares subject to possible redemption (in shares) The amount of deferred underwriting commissions assumed from the underwriting agreement related to the initial public offering. Deferred Underwriting Commissions Assumed in Underwriting Agreement Deferred underwriting commissions The cash outflow associated with cash deposit in trust account during the period. Cash Deposited in Trust Account Cash deposited in Trust Account The amount of change in value of common stock subject to redemption from noncash transactions. Increase (Decrease) in Value of Common Stock Subject to Redemption Change in value of Class A ordinary shares subject to possible redemption The amount of offering costs from noncash transactions included in note payable. Offering Costs Included in Note Payable Offering costs funded with note payable The amount of initial classification of common stock subject to redemption from noncash transactions. Initial value of Class A common stock subject to possible redemption Initial value of Class A ordinary shares subject to possible redemption The amount of deferred offering costs paid by sponsor in exchange for ordinary shares in noncash financing activities. Deferred Offering Costs Paid by Sponsor in Exchange for Issuance of Ordinary Shares Deferred offering costs paid by Sponsor in exchange for issuance of Class B ordinary shares Offering costs paid by sponsor in exchange for issuance of founder shares The amount of offering costs from noncash transactions included in accrued expenses. Offering Costs Included in Accrued Expenses Offering costs included in accrued expenses