Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Weighted-average shares used in basic earnings per share calculations		504.0	507.4	507.1	506.8
Stock options, restricted stock units and other equity-based awards		5.4	6.8	6.6	7.6
Weighted-average shares used in diluted earnings per share calculations		509.4	514.2	513.7	514.4
Income from continuing operations:
Income from continuing operations		$ 134	$ 306	$ 535	$ 725
Less: net income from continuing operations attributable to noncontrolling interests		35	4	103	4
Income from continuing operations available to Genworth Financial, Inc.'s common stockholders		$ 99	$ 302	$ 432	$ 721
Basic per share		$ 0.2	$ 0.59	$ 0.85	$ 1.42
Diluted per share		$ 0.19	$ 0.59	$ 0.84	$ 1.4
Income (loss) from discontinued operations:
Income (loss) from discontinued operations, net of taxes		$ 5	$ 12	$ 2	$ 28
Less: net income from discontinued operations attributable to noncontrolling interests		0	0	0	8
Income from discontinued operations available to Genworth Financial, Inc.'s common stockholders		$ 5	$ 12	$ 2	$ 20
Basic per share		$ 0.01	$ 0.02	$ 0	$ 0.04
Diluted per share		$ 0.01	$ 0.02	$ 0	$ 0.04
Net income:
Income from continuing operations		$ 134	$ 306	$ 535	$ 725
Income (loss) from discontinued operations, net of taxes		5	12	2	28
Net income		139	318	537	753
Less: net income attributable to noncontrolling interests		35	4	103	12
Net income available to Genworth Financial, Inc.'s common stockholders		$ 104	$ 314	$ 434	$ 741
Basic per share	[1]	$ 0.21	$ 0.62	$ 0.86	$ 1.46
Diluted per share	[1]	$ 0.2	$ 0.61	$ 0.85	$ 1.44

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