Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Fiscal Year Focus	2020
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-38334
Entity Registrant Name	Immersion Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3180138
Entity Address, Address Line One	330 Townsend Street, Suite 234
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94107
City Area Code	408
Local Phone Number	467-1900
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	IMMR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 80,883,149
Entity Common Stock, Shares Outstanding		30,088,019
Entity Central Index Key	0001058811
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference	Items 10 (as to directors and Delinquent Section 16(a) Reports (if any)), 11, 12 (as to Beneficial Ownership), 13 and 14 of Part III of this Annual Report on Form 10-K incorporate by reference portions of the Registrant’s definitive Proxy Statement for the 2021 Annual Meeting of Stockholders.
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false