| Cover - USD ($) | 12 Months Ended | ||
| Dec. 31, 2019 | Apr. 01, 2020 | Jun. 30, 2019 | |
| Cover [Abstract] | |||
| Document Type | 10-K/A | ||
| Amendment Flag | true | ||
| Amendment Description | This Amendment No. 1 (this "Amendment") on Form 10-K/A is being filed with respect to Genworth Financial, Inc.'s Annual Report on Form 10-K for the fiscal year ended December 31, 2019 filed with the Securities and Exchange Commission (the "SEC") on February 27, 2020 (the "Form 10-K"). This Amendment updates Part III to contain certain additional information required therein. | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Document Period End Date | Dec. 31, 2019 | ||
| Document Fiscal Period Focus | FY | ||
| Document Fiscal Year Focus | 2019 | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity File Number | 001-32195 | ||
| Entity Registrant Name | GENWORTH FINANCIAL, INC. | ||
| Entity Central Index Key | 0001276520 | ||
| Entity Tax Identification Number | 80-0873306 | ||
| Entity Incorporation, State or Country Code | DE | ||
| Entity Address, Address Line One | 6620 West Broad Street | ||
| Entity Address, City or Town | Richmond | ||
| Entity Address, State or Province | VA | ||
| Entity Address, Postal Zip Code | 23230 | ||
| City Area Code | (804) | ||
| Local Phone Number | 281-6000 | ||
| Title of 12(b) Security | Class A Common Stock, par value $.001 per share | ||
| Trading Symbol | GNW | ||
| Security Exchange Name | NYSE | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| 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 | ||
| Entity Shell Company | false | ||
| Entity Public Float | $ 1,900,000,000 | ||
| Entity Common Stock, Shares Outstanding | 505,126,098 |
