Schedule II Genworth Financial, Inc. (Parent Company Only) - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	12 Months Ended
	Jan. 01, 2017	Oct. 21, 2016	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Apr. 01, 2013
Condensed Financial Statements, Captions [Line Items]
Deferred tax asset				$ 1,365	$ 1,464
Current income tax payable				19
Net cash received (paid) for taxes				(31)	(33)	$ (46)
Accounting for Stock Compensation
Condensed Financial Statements, Captions [Line Items]
Deferred tax asset	$ 9
Parent Company
Condensed Financial Statements, Captions [Line Items]
Deferred tax asset				13	14
Deferred tax asset			$ 18
TCJA, impact from change in tax rate, percent			21.00%
Current income tax receivable					11
Current income tax payable				4
Net cash received (paid) for taxes				$ 21	$ (16)	$ 32
Parent Company | Accounting for Stock Compensation
Condensed Financial Statements, Captions [Line Items]
Deferred tax asset	$ 9
China Oceanwide Holdings Group Co., Ltd. | Definitive Acquisition Agreement
Condensed Financial Statements, Captions [Line Items]
Total transaction value to acquire all of our outstanding common stock		$ 2,700
Per share amount to acquire all of our outstanding common stock		$ 5.43
Genworth Holdings
Condensed Financial Statements, Captions [Line Items]
Percentage of subsidiary equity ownership							100.00%