Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements as of June 30, 2023 and December 31, 2022, and for the three and six months ended June 30, 2023 and 2022, have been presented in conformity with accounting principles generally accepted in the United States of America (“GAAP”).
Principles of Consolidation	Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of Exicure and its wholly owned subsidiary, Exicure Operating Company. All intercompany transactions and accounts are eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on certain assumptions which it believes are reasonable in the circumstances and while actual results could differ from those estimates, management does not believe that any change in those assumptions in the near term would have a significant effect on the Company’s financial position, results of operations or cash flows. Actual results in future periods could differ from those estimates.
Investment in Convertible Notes Receivable	Investment in Convertible Notes Receivable Securities are classified as current or noncurrent based on the remaining contractual maturities of the securities. Securities are designated by the Company at the point of investment, as either trading, AFS, or held to maturity. Under ASC 825, Financial Instruments, the Company elected the fair value option for all outstanding convertible notes receivable. Management evaluates the performance of the securities on a fair value basis. Under the fair value option, the notes receivable are measured at each reporting period based upon their exit value in an orderly transaction and unrealized gains or losses from changes in fair value are recorded in the Condensed Consolidated Statements of Operations.
Recent Accounting Pronouncements Adopted	Recent Accounting Pronouncements Adopted Financial Instruments - Credit Losses In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) (“ASU 2016-13”). This ASU changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The standard replaces the “incurred loss” approach with an “expected loss” model. The new model, referred to as the current expected credit loss (“CECL”) model, will apply to: (1) financial assets subject to credit losses and measured at amortized cost, and (2) certain off-balance sheet credit exposures. ASU 2016-13 also expands the disclosure requirements regarding an entity’s assumptions, models, and methods for estimating the allowance for credit losses. ASU No. 2016-13 was effective for the Company beginning on January 1, 2020. The Company adopted this ASU in January 2023. There was no material impact on the condensed consolidated financial statements.
Loss Per Common Share	Basic loss per common share is calculated by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted loss per common share is calculated using the treasury share method by giving effect to all potentially dilutive securities that were outstanding. Potentially dilutive options, restricted stock units and warrants to purchase common stock that were outstanding during the periods presented were excluded from the diluted loss per share calculation for the periods presented because such shares had an anti-dilutive effect due to the net loss reported in those periods.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2023

The accompanying unaudited condensed consolidated financial statements as of June 30, 2023 and December 31, 2022, and for the three and six months ended June 30, 2023 and 2022, have been presented in conformity with accounting principles generally accepted in the United States of America (“GAAP”).

Principles of Consolidation

The accompanying unaudited condensed consolidated financial statements include the accounts of Exicure and its wholly owned subsidiary, Exicure Operating Company. All intercompany transactions and accounts are eliminated in consolidation.

Use of Estimates

The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on certain assumptions which it believes are reasonable in the circumstances and while actual results could differ from those estimates, management does not believe that any change in those assumptions in the near term would have a significant effect on the Company’s financial position, results of operations or cash flows. Actual results in future periods could differ from those estimates.

Investment in Convertible Notes Receivable

Securities are classified as current or noncurrent based on the remaining contractual maturities of the securities. Securities are designated by the Company at the point of investment, as either trading, AFS, or held to maturity. Under ASC 825, Financial Instruments, the Company elected the fair value option for all outstanding convertible notes receivable. Management evaluates the performance of the securities on a fair value basis. Under the fair value option, the notes receivable are measured at each reporting period based upon their exit value in an orderly transaction and unrealized gains or losses from changes in fair value are recorded in the Condensed Consolidated Statements of Operations.

Recent Accounting Pronouncements Adopted

Financial Instruments - Credit Losses

In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) (“ASU 2016-13”). This ASU changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The standard replaces the “incurred loss” approach with an “expected loss” model. The new model, referred to as the current expected credit loss (“CECL”) model, will apply to: (1) financial assets subject to credit losses and measured at amortized cost, and (2) certain off-balance sheet credit exposures. ASU 2016-13 also expands the disclosure requirements regarding an entity’s assumptions, models, and methods for estimating the allowance for credit losses. ASU No. 2016-13 was effective for the Company beginning on January 1, 2020. The Company adopted this ASU in January 2023. There was no material impact on the condensed consolidated financial statements.

Loss Per Common Share

Basic loss per common share is calculated by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted loss per common share is calculated using the treasury share method by giving effect to all potentially dilutive securities that were outstanding. Potentially dilutive options, restricted stock units and warrants to purchase common stock that were outstanding during the periods presented were excluded from the diluted loss per share calculation for the periods presented because such shares had an anti-dilutive effect due to the net loss reported in those periods.