| Cover | 12 Months Ended |
| Dec. 31, 2020 shares |
| Document Information [Line Items] | |
| Document Type | 20-F/A |
| Amendment Flag | true |
| Document Period End Date | Dec. 31, 2020 |
| Document Fiscal Year Focus | 2020 |
| Document Fiscal Period Focus | FY |
| Entity Registrant Name | Qudian Inc. |
| Entity Central Index Key | 0001692705 |
| Current Fiscal Year End Date | --12-31 |
| Entity Well-known Seasoned Issuer | No |
| Entity Current Reporting Status | Yes |
| Entity Filer Category | Accelerated Filer |
| Entity Emerging Growth Company | false |
| Entity Shell Company | false |
| Document Annual Report | true |
| Document Shell Company Report | false |
| Document Transition Report | false |
| Document Registration Statement | false |
| Document Accounting Standard | U.S. GAAP |
| Entity Voluntary Filers | No |
| Entity Interactive Data Current | Yes |
| Entity File Number | 001-38230 |
| Entity Incorporation, State or Country Code | E9 |
| Entity Address, Address Line One | Tower A, AVIC Zijin Plaza |
| Entity Address, City or Town | Siming District |
| Entity Address, Postal Zip Code | 361000 |
| Entity Address, Country | CN |
| ICFR Auditor Attestation Flag | true |
| Auditor Name | Ernst & Young Hua Ming LLP |
| Auditor Firm ID | 1408 |
| Auditor Location | Shanghai, The People’s Republic of China |
| Amendment Description | This Amendment No. 1 on Form 20-F/A (the “Amendment”) is being filed by Qudian Inc. (the “Company,” “we,” “our,” or “us”) to amend the Company’s Annual Report on Form 20-F for the fiscal year ended December 31, 2020, originally filed with the U.S. Securities Exchange Commission on April 29, 2021 (the “Original Filing”). The Company is filing this Amendment to (i) include the financial statements and related notes of Secoo Holding Limited (“Secoo”), as required by Rule 3-09 of Regulation S-X under the Securities Exchange Act of 1934, as amended (“Rule 3-09”) and (ii) amend Item 15 of Part II of the Original Filing to revise management’s conclusion with respect to its evaluation of the effectiveness of the Company’s disclosure controls and procedures, as defined in Rules 13a-15(e) and 15d-15(e) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Rule 3-09 requires, among other things, that separate financial statements for unconsolidated subsidiaries and investees accounted for by the equity method to be included in the Form 20-F when such entities are individually significant. We have determined that our equity method investment in Secoo, which is elected to be measured at fair value and not consolidated in our financial statements, was significant under Rule 1-02(w) and Rule 3-09 of Regulation S-X in relation to our financial results for the years ended December 31, 2020 and 2021. This Amendment is therefore filed to supplement the Original Filing with the inclusion of the financial statements and related notes of Secoo as of December 31, 2020 and 2021 and for the years ended December 31, 2020 and 2021 (the “Financial Statements of Secoo”). This Form 20-F/A consists solely of the cover page, this explanatory note, Items 15 and 19 of Part II, the Financial Statements of Secoo, certifications by our chief executive officer and principal financial officer, and the consent of the registered public accounting firm of Secoo. This Amendment does not affect any other parts of, or exhibits to, the Original Filing, nor does it reflect events occurring after the date of the Original Filing. Accordingly, this Amendment should be read in conjunction with the Original Filing and with our filings with the U.S. Securities and Exchange Commission (the “SEC”) subsequent to the Original Filing. |
| Business Contact [Member] | |
| Document Information [Line Items] | |
| Entity Address, Address Line One | Tower A, AVIC Zijin Plaza |
| Entity Address, City or Town | Siming District |
| Entity Address, Postal Zip Code | 361000 |
| Entity Address, Country | CN |
| Contact Personnel Name | Min Luo, Chairman and Chief Executive Officer |
| Contact Personnel Email Address | ir@qudian.com |
| Country Region | 86 |
| City Area Code | 592 |
| Local Phone Number | 5911580 |
| Class A Voting Ordinary Shares [Member] | |
| Document Information [Line Items] | |
| Entity Common Stock, Shares Outstanding | 189,514,026 |
| Title of 12(b) Security | Class A Ordinary Shares |
| No Trading Symbol Flag | true |
| Class B Voting Ordinary Shares [Member] | |
| Document Information [Line Items] | |
| Entity Common Stock, Shares Outstanding | 63,491,172 |
| American Depositary Shares [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | American Depositary Shares |
| Trading Symbol | QD |
| Security Exchange Name | NYSE |
