Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 25, 2022	Jun. 30, 2021
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	001-39160
Entity Registrant Name	Fisker Inc./DE
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3100340
Entity Address, Address Line One	1888 Rosecrans Avenue
Entity Address, City or Town	Manhattan Beach
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90266
City Area Code	833
Local Phone Number	434-7537
Title of 12(b) Security	Class A Common Stock, par value of $0.00001 per share
Trading Symbol	FSR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 2,623.9
Documents Incorporated by Reference	Part III incorporates by reference certain information from the registrant’s definitive proxy statement (the “Proxy Statement”) relating to its 2022 Annual Meeting of Stockholders. The Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Entity Central Index Key	0001720990
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		164,438,482
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		132,354,128