Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2021	Feb. 16, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Central Index Key	0001276520
Current Fiscal Year End Date	--12-31
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Entity Registrant Name	GENWORTH FINANCIAL, INC.
Entity File Number	001-32195
Entity Tax Identification Number	80-0873306
Entity Incorporation, State or Country Code	DE
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Address, Address Line One	6620 West Broad Street
Entity Address, State or Province	VA
Entity Address, City or Town	Richmond
Entity Address, Postal Zip Code	23230
Entity Interactive Data Current	Yes
City Area Code	804
Local Phone Number	281-6000
Trading Symbol	GNW
Security Exchange Name	NYSE
Title of 12(b) Security	Class A Common Stock, par value $.001 per share
Entity Common Stock, Shares Outstanding		507,385,834
Entity Public Float			$ 2.0
ICFR Auditor Attestation Flag	true
Auditor Name	KPMG LLP
Auditor Firm ID	185
Auditor Location	Richmond, VA