Schedule II Genworth Financial, Inc. (Parent Company Only) (Statements of Income) (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2020		Sep. 30, 2020		Jun. 30, 2020		Mar. 31, 2020		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Net investment income																	$ 3,260	$ 3,220	$ 3,121
Total revenues	$ 2,263	[1]	$ 2,420	[1]	$ 2,138	[1]	$ 1,837	[1]	$ 2,038		$ 2,020		$ 1,994		$ 2,044		8,658	8,096	7,901
Expenses:
Acquisition and operating expenses, net of deferrals																	988	962	943
Interest expense																	202	239	256
Loss before income taxes and equity in income of subsidiaries																	1,031	714	137
Benefit from income taxes																	270	195	70
Income from continuing operations	297		417		79		(66)		36		128		143		148		727	455	(3)
Income from discontinued operations, net of taxes	(30)	[2]	1	[2]	(520)	[2]	0	[2]	(31)	[3]	(80)	[3]	60	[3]	62	[3]	(549)	11	230
Net income (loss) available to Genworth Financial, Inc.'s common stockholders	$ 267		$ 418		$ (441)		$ (66)		$ (17)		$ 18		$ 168		$ 174		178	343	119
Parent Company
Revenues:
Net investment income																	(3)	(3)	(3)
Total revenues																	(3)	(3)	(3)
Expenses:
Acquisition and operating expenses, net of deferrals																	31	20	33
Interest expense																	1	3	2
Total expenses																	32	23	35
Loss before income taxes and equity in income of subsidiaries																	(35)	(26)	(38)
Benefit from income taxes																	(2)	(3)	(6)
Equity in income of subsidiaries																	210	366	151
Income from continuing operations																	177	343	119
Income from discontinued operations, net of taxes																	1	0	0
Net income (loss) available to Genworth Financial, Inc.'s common stockholders																	$ 178	$ 343	$ 119

[1] In the fourth quarter of 2020, we recorded lower net investment gains as compared to the third quarter of 2020. The higher net investment gains recorded in the third quarter of 2020 related to the sale of available-for-sale fixed maturity securities of $330 million driven primarily from the sale of U.S. government securities due to portfolio rebalancing and asset exposure management as a result of the prolonged low interest rate environment. This decrease to total revenues was partially offset by higher net investment income recorded in the fourth quarter of 2020 largely driven by bond calls and mortgage loan repayments of $40 million and limited partnerships of $38 million.

[2] In the fourth quarter of 2020, we recorded a loss from discontinued operations, net of taxes, of $30 million principally attributed to foreign currency remeasurement losses of $26 million, unfavorable tax charges of $17 million and other expenses of $8 million, mostly consisting of interest expense attributable to the promissory note owed to AXA. These losses were partially offset by derivative hedge gains of $21 million associated with foreign currency forward contracts entered into to mitigate our exposure to the installment payments to be made in British Pounds in 2022. See note 23 for additional details on discontinued operations.

[3] In the fourth quarter of 2019, we recorded an after-tax loss of approximately $110 million principally in connection with pending litigation involving our former lifestyle protection insurance business. See note 20 for additional information related to asserted claims regarding the sale of our lifestyle protection insurance business. We completed the sale of Genworth MI Canada Inc. (“Genworth Canada”) on December 12, 2019 and recorded an incremental gain of $43 million in the fourth quarter of 2019 predominantly related to a favorable tax position refinement. In addition, during the fourth quarter of 2019 through the sale closing date of December 12, 2019, we recorded $36 million of income from discontinued operations attributed to Genworth Canada.