Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2022		Sep. 30, 2022		Jun. 30, 2022		Mar. 31, 2022		Dec. 31, 2021		Sep. 30, 2021		Jun. 30, 2021		Mar. 31, 2021		Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Quarterly Results Of Operations [Abstract]
Total revenues	$ 1,895		$ 1,839		$ 1,881		$ 1,892		$ 1,736	[1]	$ 2,070	[1]	$ 2,041	[1]	$ 1,985	[1]	$ 7,507		$ 7,832		$ 8,284
Total benefits and expenses	1,635	[2],[3]	1,653	[2],[3]	1,588	[2],[3]	1,653	[2],[3]	1,481	[4]	1,697	[4]	1,721	[4]	1,752	[4]	6,529		6,651		7,356
Income (loss) from continuing operations	204	[2],[3]	134	[2],[3]	220	[2],[3]	181	[2],[3]	193	[1],[4],[5]	306	[1],[4],[5]	245	[1],[4],[5]	174	[1],[4],[5]	739		918		698
Income (loss) from discontinued operations, net of taxes	(2)		5		(1)		(2)		(1)		12		(5)		21		0		27		(486)
Net income	202	[2],[3]	139	[2],[3]	219	[2],[3]	179	[2],[3]	192	[1],[4],[5]	318	[1],[4],[5]	240	[1],[4],[5]	195	[1],[4],[5]	739		945		212
Net income from continuing operations attributable to noncontrolling interests	27		35		38		30		29	[6]	4	[6]	0	[6]	0	[6]	130		33		0
Net income from discontinued operations attributable to noncontrolling interests	0		0		0		0		0		0		0		8		0		8		34
Net income available to Genworth Financial, Inc.'s common stockholders	175	[2],[3]	104	[2],[3]	181	[2],[3]	149	[2],[3]	163	[6]	314	[6]	240	[6]	187	[6]	609		904		178
Net income available to Genworth Financial, Inc.'s common stockholders:
Income from continuing operations available to Genworth Financial, Inc.'s common stockholders	177		99		182		151		164		302		245		174		609		885		698
Income (loss) from discontinued operations available to Genworth Financial, Inc.'s common stockholders	(2)		5		(1)		(2)		(1)		12		(5)		13		0		19		(520)
Net income available to Genworth Financial, Inc.'s common stockholders	$ 175	[2],[3]	$ 104	[2],[3]	$ 181	[2],[3]	$ 149	[2],[3]	$ 163	[6]	$ 314	[6]	$ 240	[6]	$ 187	[6]	$ 609		$ 904		$ 178
Income from continuing operations available to Genworth Financial, Inc.'s common stockholders per share:
Basic	$ 0.36		$ 0.2		$ 0.36		$ 0.3		$ 0.32		$ 0.59		$ 0.48		$ 0.35		$ 1.21		$ 1.75		$ 1.38
Diluted	0.35		0.19		0.36		0.29		0.32		0.59		0.47		0.34		1.19		1.72		1.36
Net income available to Genworth Financial, Inc.'s common stockholders per share:
Basic	0.35		0.21		0.36		0.29		0.32		0.62		0.47		0.37		1.21	[7]	1.78	[7]	0.35	[7]
Diluted	$ 0.35		$ 0.2		$ 0.35		$ 0.29		$ 0.32		$ 0.61		$ 0.47		$ 0.37		$ 1.19	[7]	$ 1.76	[7]	$ 0.35	[7]
Weighted-average common shares outstanding:
Basic	496.7		504.0		509.0		508.3		507.4		507.4		507.0		506.0		504.5		506.9		505.2
Diluted	503.2		509.4		514.2		517.4		515.6		514.2		515.0		513.8		511.0		514.7		511.6

[1] In the fourth quarter of 2021, our life insurance business initially ceded $360 million of premiums associated with certain term life insurance policies under a new reinsurance treaty as part of a life block transaction.

[2] In the fourth quarter of 2022, our Enact segment recorded a pre-tax net favorable reserve adjustment of $42 million primarily related to COVID-19 delinquencies in 2020 and 2021 curing at levels above original reserve expectations.

[3] In the fourth quarter of 2022, our life insurance business completed its annual review of assumptions for its universal and term universal life insurance products and recorded a pre-tax favorable unlocking of $43 million mostly attributable to higher interest rates.

[4] In the fourth quarter of 2021, our life insurance business initially ceded $268 million of certain term life insurance reserves under a new reinsurance treaty as part of a life block transaction. Our life insurance business also completed its annual review of assumptions in the fourth quarter of 2021. This review resulted in higher total benefits and expenses of $87 million from an unfavorable unlocking in our term universal and universal life insurance products largely attributable to higher pre-COVID-19 mortality. In our term universal life insurance products, we also recorded a DAC impairment of $41 million in the fourth quarter of 2021 principally due to lower future estimated gross profits.

[5] In the fourth quarter of 2021, our life insurance business recorded a net loss of $131 million predominantly driven by an initial loss of $73 million as a result of ceding certain term life insurance policies as part of a life block transaction, an unfavorable unlocking of $70 million associated with its annual review of assumptions and a DAC impairment of $32 million as a result of recoverability testing.

[6] On September 20, 2021, we completed the minority IPO of Enact Holdings, which reduced our ownership percentage to 81.6%, and lowered our available net income by $29 million in the fourth quarter of 2021.

[7] May not total due to whole number calculation.