75000 - Document - Document and Entity Information link:presentationLink link:calculationLink link:definitionLink 75010 - Statement - Statements of Financial Condition (Unaudited) link:presentationLink link:calculationLink link:definitionLink 75020 - Statement - Statements of Financial Condition (Parenthetical) (Unaudited) link:presentationLink link:calculationLink link:definitionLink 75030 - Statement - Statements of Comprehensive Income (Unaudited) link:presentationLink link:calculationLink link:definitionLink 75040 - Statement - Statements of Changes in Shareholders' Equity and Redeemable Capital Shares (Unaudited) link:presentationLink link:calculationLink link:definitionLink 75050 - Statement - Statements of Cash Flows (Unaudited) link:presentationLink link:calculationLink link:definitionLink 995455 - Disclosure - Background link:presentationLink link:calculationLink link:definitionLink 995465 - Disclosure - Organization link:presentationLink link:calculationLink link:definitionLink 995475 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 995485 - Disclosure - Swiss Franc Deposits link:presentationLink link:calculationLink link:definitionLink 995495 - Disclosure - Concentration Risk link:presentationLink link:calculationLink link:definitionLink 995505 - Disclosure - Service Providers and Related Party Agreements link:presentationLink link:calculationLink link:definitionLink 995515 - Disclosure - Share Purchases and Redemptions link:presentationLink link:calculationLink link:definitionLink 995525 - Disclosure - Commitments and Contingencies link:presentationLink link:calculationLink link:definitionLink 995535 - Disclosure - Summary of Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 995545 - Disclosure - Summary of Significant Accounting Policies (Tables) link:presentationLink link:calculationLink link:definitionLink 995555 - Disclosure - Organization - Additional Information (Detail) link:presentationLink link:calculationLink link:definitionLink 995565 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Detail) link:presentationLink link:calculationLink link:definitionLink 995575 - Disclosure - Summary of Significant Accounting Policies - Summary of Distributions Per Share and in Total for the Periods Presented (Details) link:presentationLink link:calculationLink link:definitionLink 995585 - Disclosure - Swiss Franc Deposits - Additional Information (Detail) link:presentationLink link:calculationLink link:definitionLink 995595 - Disclosure - Service Providers and Related Party Agreements - Additional Information (Detail) link:presentationLink link:calculationLink link:definitionLink 995605 - Disclosure - Share Purchases and Redemptions - Additional Information (Detail) link:presentationLink link:calculationLink link:definitionLink Related Party Transaction [Table] Schedule Of Related Party Transactions By Related Party [Table] Common Stock, Dividends, Per Share, Cash Paid Distributions per Share Rate of distribution per share Federal Home Loan Banks [Abstract] Commitments and Contingencies Commitments and Contingent Liabilities (Note 8) Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted, Total Diluted Weighted-average Shares Outstanding Redeemable Noncontrolling Interest, Equity, Carrying Amount [Abstract] Redeemable Capital Shares and Shareholders’ Equity Interest Receivable, Current Receivable from accrued interest Interest income. Interest Income Policy [Text Block] Interest Income Income Tax Expense (Benefit) Provision for federal income taxes Income Tax Expense (Benefit), Total Stockholders Equity Period Increase Decrease Due To Share Transactions Net Increase (Decrease) due to Share Transactions Stockholders equity period increase (decrease) due to share transactions. Proceeds from Issuance of Redeemable Preferred Stock Proceeds from purchases of redeemable capital Shares Principal deposits Related Party Transaction [Line Items] Related Party Transaction [Line Items] Subsequent Event Type [Domain] Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Effect of exchange rate on cash Distribution Made to Limited Partner, Cash Distributions Paid Distributions paid Related and Nonrelated Parties [Domain] Related Party Earnings Per Share, Basic Basic Earnings (Loss) per Share Earnings Per Share, Basic, Total Document Period End Date Document Period End Date Statement of Stockholders' Equity [Abstract] Accounting Policies [Table] Accounting Policies [Table] Accounting Policies [Table] Foreign Currency Transactions and Translations Policy [Policy Text Block] Foreign Currency Translation Temporary Equity Disclosure [Abstract] Assets Total Assets Title of 12(b) Security Title of 12(b) Security Related Party Transaction [Axis] Related Party Transaction Minimum period required to stay for tax liability. Minimum Period Required To Stay For Tax Liability Minimum days required to stay for tax liability Interest Paid, Excluding Capitalized Interest, Operating Activity Cash paid for interest Cash paid for interest Rule 10b5-1 Arr Modified [Flag] Rule 10b5-1 Arrangement Modified Flag. Rule 10b5-1 Arrangement Modified Interest Expense, Operating Interest Expense, Operating, Total Interest Expense on currency deposits Cash Deposits, interest bearing Increase (Decrease) in Interest Payable, Net Accrued interest expense Entity Address, Address Line Two Entity Address, Address Line Two Redeemable capital shares. Redeemable Capital Shares [Member] Redeemable Capital Shares [Member] Professional fees liability. Professional Fees Liability [Member] Professional Fees Liability [Member] Payments for Operating Activities Withdrawals (to pay expenses) Payments for Operating Activities, Total Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Temporary Equity, Par or Stated Value Per Share Redeemable Capital Shares, no par value Entity Interactive Data Current Entity Interactive Data Current Business Description and Basis of Presentation [Text Block] Background Liabilities Total Liabilities Partners' Capital Notes Disclosure [Text Block] Summary of Distributions per Share Non Recurring Fees And Expenses Policy [Text Block] Non-Recurring Fees and Expenses Non recurring fees and expenses. Retained Earnings Retained Earnings (Accumulated Deficit) Retained Earnings (Accumulated Deficit), Total Operating Expenses Total Expenses Operating Expenses, Total Revenues [Abstract] Income Number of deposits accounts in which trust assets primarily consist demand deposit. Number Of Deposits Accounts In Which Trust Assets Primarily Consist Demand Deposit Number of deposits accounts in which trust's assets primarily consist of Swiss Francs Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Change in operating assets and liabilities: Other Liability, Current, Related Party [Extensible Enumeration] Stock Issued During Period, Shares, New Issues Purchases of Shares, Shares Related Party Transactions [Abstract] Income Tax, Policy [Policy Text Block] Federal Income Taxes Total Liabilities, Redeemable Capital Shares and Shareholders' Equity Liabilities and Equity Stockholders' equity, net increase (decrease) in number of shares due to share transactions. Stockholders Equity Net Increase Decrease Due To Share Transactions In Shares Net Increase (Decrease) due to Share Transactions, Shares Document Fiscal Period Focus Document Fiscal Period Focus Costs and Expenses [Abstract] Expenses Receivable from accrued interest Increase (Decrease) in Accrued Interest Receivable, Net Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Net change in cash Entity Current Reporting Status Entity Current Reporting Status Use of Estimates, Policy [Policy Text Block] Accounting Estimates Document Transition Report Document Transition Report Concentration Risk Concentration Risk Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Temporary Equity, Carrying Amount, Period Increase (Decrease) Adjustment of Redeemable Capital Shares to Redemption Value Temporary Equity, Carrying Amount, Period Increase (Decrease), Total Shareholders' Equity: Equity, Attributable to Parent [Abstract] Weighted-average Shares Outstanding Weighted Average Number of Shares Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic, Total Basic Weighted-average Shares Outstanding Assets [Abstract] Assets Entity Central Index Key Entity Central Index Key Other Liabilities, Current Accrued Sponsor's fee Interest-Bearing Deposits in Banks and Other Financial Institutions, Total Interest-Bearing Deposits in Banks and Other Financial Institutions Swiss Franc deposits, interest bearing Current Fiscal Year End Date Current Fiscal Year End Date Document Quarterly Report Document Quarterly Report Balance Redeemable Noncontrolling Interest, Equity, Carrying Amount Balance Redeemable Noncontrolling Interest, Equity, Carrying Amount, Total Redeemable Capital Shares, at redemption value, no par value, 3,950,000 and 3,550,000 issued and outstanding, respectively Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Net cash provided by (used in) operating activities Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Earnings Per Share, Diluted Diluted Earnings (Loss) per Share Earnings Per Share, Diluted, Total Net Comprehensive Income (Loss) Net Comprehensive Income (Loss) Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Equity Components [Axis] Equity Components Statement of Cash Flows [Abstract] Cash and Cash Equivalents Disclosure [Text Block] Swiss Franc Deposits Annual nominal rate Investment Interest Rate Annual nominal rate Cash at Depository Cash at depository. U.S. Dollar Cash at Depository Stock Redeemable In Baskets Number Of Shares Redemptions Capital Shares, Number of shares in each Block Stock redeemable number share each block shares. Number of operating segment Number of Operating Segments Temporary Equity, Shares Outstanding Balance, Shares Balance, Shares Redeemable Capital Shares, shares outstanding Segment Reporting, Policy [Policy Text Block] Segment Reporting Sponsor [Member] Sponsor [Member] Sponsor. Accrued professional fees. Accrued Professional Fees [Member] Accrued Professional Fees [Member] Document Type Document Type Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Cash flows from operating activities Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] Subsequent Event [Member] Subsequent Event [Member] Dividends, Common Stock, Cash Total distribution Distributions Net Change Noninterest-Bearing Deposits, Foreign Increase (decrease) in payable for Swiss Franc deposits overdrawn Stock Redeemed or Called During Period, Value Redemption of Shares Securities Act File Number Entity File Number Redemptions Payable Redemptions payable. Redemptions payable Retained Earnings [Member] Retained Earnings [Member] Entity Registrant Name Entity Registrant Name Accounting Policies [Abstract] Distributions Dividends [Policy Text Block] Dividends Policy [Text Block] Non-Rule 10b5-1 Arr Modified [Flag] Non-Rule 10b5-1 Arr modified flag. Non-Rule 10b5-1 Arrangement Modified Entity Address, Address Line One Entity Address, Address Line One Routine Operational Administrative And Other Ordinary Expenses Policy [Text Block] Routine Operational, Administrative and Other Ordinary Expenses Routine operational administrative and other ordinary expenses. Supplemental Cash Flow Information [Abstract] Supplemental disclosure of cash flow information Related Party Transactions Disclosure [Text Block] Service Providers and Related Party Agreements Entity Small Business Entity Small Business Schedule of Dividends Payable [Table Text Block] Summary of Distributions Per Share and in Total for the Periods Presented Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies Accounting Policies [Line Items] Accounting Policies [Line Items] [Line Items for Accounting Policies [Table] Minimum Threshold Excess Annual Amount Of Payments Legal Fees And Expenses Excess amount of assumed audit fees and legal expenses Represents the minimum threshold for legal fees and expenses. Subsequent Event Type [Axis] Equity [Text Block] Share Purchases and Redemptions Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Cash flows from financing activities Entity Incorporation, Date of Incorporation Organization formation date Noninterest-Bearing Deposit Liabilities, Foreign Swiss Franc deposits, non-interest bearing, overdrawn Interest Payable Accrued interest expense on currency deposits Liabilities [Abstract] Liabilities Entity Tax Identification Number Entity Tax Identification Number Reclassifications of Temporary to Permanent Equity Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings Equity Component [Domain] Equity Component Entity Address, City or Town Entity Address, City or Town Stock Redeemed or Called During Period, Shares Redemption of Shares, Shares Redemption of Shares, Shares Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Share Purchase And Redemptions Settlement Period Creation And Redemption Share Purchases and Redemptions, Settlement of each creation or redemption period Share purchase and redemptions settlement period creation and redemption. Statement [Table] Statement [Table] Entity Shell Company Entity Shell Company Statement [Line Items] Statement [Line Items] Temporary Equity, Shares Issued Redeemable Capital Shares, shares issued Investment Income, Interest Interest Income Risks and Uncertainties [Abstract] Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Noncash Item [Abstract] Adjustments to reconcile net comprehensive income (loss) to net cash provided by (used in) operating activities: Related Party Transaction [Domain] Related Party Transaction Document Fiscal Year Focus Document Fiscal Year Focus Maximum Threshold Annual Amount Of Payments Legal Fees And Expenses Legal fees and expenses assumed Legal fees and expenses assumed sponsor. Statement of Comprehensive Income [Abstract] Related Party [Member] Security Exchange Name Security Exchange Name Revenues Total Income Related and Nonrelated Parties [Axis] Related Party Entity Address, State or Province Entity Address, State or Province Due from Banks Swiss Franc deposits, non-interest bearing Amendment Flag Amendment Flag Related Party Transaction, Rate Sponsor's fee accrues daily and paid monthly, annual nominal Rate Payments of Capital Distribution Distributions paid to shareholders Payments for Repurchase of Redeemable Preferred Stock Principal redemptions Redemptions of redeemable capital Shares Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Cash at end of period Cash at beginning of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Total City Area Code City Area Code Organization, Consolidation and Presentation of Financial Statements [Abstract] Sponsor Fees Sponsor’s fee Cash and Cash Equivalents [Abstract] Trading Symbol Trading Symbol Entity Emerging Growth Company Entity Emerging Growth Company Distributions paid Payments of Dividends, Total Payments of Dividends Distributions paid to shareholders Cover [Abstract] Partners' Capital, Distribution Amount Per Share Distributions per Share Stock Issued During Period, Value, Acquisitions Purchases of Shares Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Net cash provided by (used in) financing activities Increase (Decrease) in Due to Related Parties, Current Accrued Sponsor's fee Increase (Decrease) in Due to Related Parties, Current, Total Initial incorporation deposit with bank sponsor. Initial Incorporation Deposit With Bank Sponsor Initial deposits by Sponsor, Primary deposit account Entity Filer Category Entity Filer Category Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description Entity Address, Postal Zip Code Entity Address, Postal Zip Code Statement of Financial Position [Abstract] Local Phone Number Local Phone Number