| Document and Entity Information - USD ($) $ in Millions | 12 Months Ended | ||
| Dec. 31, 2021 | Apr. 15, 2022 | Jun. 30, 2021 | |
| Cover [Abstract] | |||
| Document Type | 10-K/A | ||
| Amendment Flag | true | ||
| Amendment Description | This Amendment No. 1 on Form 10-K/A (this “Amendment”) amends the Annual Report on Form 10-K of La Jolla Pharmaceutical Company (the “Company” or “La Jolla”) for the year ended December 31, 2021, originally filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 9, 2022 (the “Original Filing”). This Amendment is being filed for the purpose of providing the information required by Items 10 through 14 of Part III of the Annual Report on Form 10-K. This information was previously omitted from the Original Filing in reliance on General Instruction G(3) to the Annual Report on Form 10-K, which permits the above-referenced Items to be incorporated in the Annual Report on Form 10-K by reference from a definitive proxy statement, if such definitive proxy statement is filed no later than 120 days after December 31, 2021. At this time, La Jolla is filing this Amendment to include Part III information in its Annual Report on Form 10-K because La Jolla does not intend to file its definitive proxy statement within 120 days of December 31, 2021. In accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Items 10 through 14 of Part III of the Original Filing are hereby amended and restated in their entirety. In addition, this Form 10-K/A amends and restates in its entirety Item 15 of Part IV of the Original Filing to include new certifications by our principal executive officer and principal financial and accounting officer under Section 302 of the Sarbanes-Oxley Act of 2002, pursuant to Rule 12b-15 under the Exchange Act. Because no financial statements have been included in this Amendment and this Amendment does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4 and 5 of such certifications have been omitted. We are not including the certifications under Section 906 of the Sarbanes-Oxley Act of 2002 as no financial statements are being filed with this Amendment. Except as described above, no other changes have been made to the Original Filing. Except as otherwise indicated herein, this Amendment continues to speak as of the date of the Original Filing, and La Jolla has not updated the disclosures contained therein to reflect any events that occurred subsequent to the date of the Original Filing. The disclosures contained in the Original Filing and in the documents incorporated therein by reference are provided as of the date of such disclosures. | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Document Period End Date | Dec. 31, 2021 | ||
| Document Fiscal Year Focus | 2021 | ||
| Document Fiscal Period Focus | FY | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity File Number | 1-36282 | ||
| Entity Registrant Name | LA JOLLA PHARMACEUTICAL COMPANY | ||
| Entity Incorporation, State or Country Code | DE | ||
| Entity Tax Identification Number | 33-0361285 | ||
| Entity Address, Address Line One | 201 Jones Road | ||
| Entity Address, Address Line Two | Suite 400 | ||
| Entity Address, City or Town | Waltham | ||
| Entity Address, State or Province | MA | ||
| Entity Address, Postal Zip Code | 02451 | ||
| City Area Code | 617 | ||
| Local Phone Number | 715-3600 | ||
| Title of 12(b) Security | Common Stock, par value $0.0001 per share | ||
| Trading Symbol | LJPC | ||
| Security Exchange Name | NASDAQ | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Entity Filer Category | Non-accelerated Filer | ||
| Entity Small Business | true | ||
| Entity Emerging Growth Company | false | ||
| Entity Shell Company | false | ||
| Entity Common Stock, Shares Outstanding | 25,621,657 | ||
| Entity Central Index Key | 0000920465 | ||
| Entity Public Float | $ 73.3 | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| ICFR Auditor Attestation Flag | false | ||
| Auditor Name | Baker Tilly US, LLP | ||
| Auditor Location | San Diego, California | ||
| Auditor Firm ID | 23 | ||
| Documents Incorporated by Reference | DOCUMENTS INCORPORATED BY REFERENCE None. |
