Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 05, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Trading Symbol	RNWK
Entity Registrant Name	RealNetworks, Inc.
Entity Central Index Key	0001046327
Entity File Number	1-37745
Current Fiscal Year End Date	--12-31
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-1628146
City Area Code	(206)
Local Phone Number	674-2700
Entity Address, Address Line One	1501 First Avenue South, Suite 600
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98134
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		46,907,403
Security Exchange Name	NASDAQ
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock, Par Value $0.001 per share
Convertible Preferred Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Preferred Share Purchase Rights