Earnings (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Weighted-average shares used in basic earnings per share calculations		509.0	507.0	508.6	506.5
Stock options, restricted stock units and other equity-based awards		5.2	8.0	7.2	7.9
Weighted-average shares used in diluted earnings per share calculations		514.2	515.0	515.8	514.4
Income from continuing operations:
Income from continuing operations		$ 220	$ 245	$ 401	$ 419
Less: net income from continuing operations attributable to noncontrolling interests		38	0	68	0
Income from continuing operations available to Genworth Financial, Inc.'s common stockholders		$ 182	$ 245	$ 333	$ 419
Basic per share		$ 0.36	$ 0.48	$ 0.65	$ 0.83
Diluted per share		$ 0.36	$ 0.47	$ 0.65	$ 0.82
Income (loss) from discontinued operations:
Income (loss) from discontinued operations, net of taxes		$ (1)	$ (5)	$ (3)	$ 16
Less: net income from discontinued operations attributable to noncontrolling interests		0	0	0	8
Income (loss) from discontinued operations available to Genworth Financial, Inc.'s common stockholders		$ (1)	$ (5)	$ (3)	$ 8
Basic per share		$ 0	$ (0.01)	$ (0.01)	$ 0.02
Diluted per share		$ 0	$ (0.01)	$ (0.01)	$ 0.02
Net income:
Income from continuing operations		$ 220	$ 245	$ 401	$ 419
Income (loss) from discontinued operations, net of taxes		(1)	(5)	(3)	16
Net income		219	240	398	435
Less: net income attributable to noncontrolling interests		38	0	68	8
Net income available to Genworth Financial, Inc.'s common stockholders		$ 181	$ 240	$ 330	$ 427
Basic per share	[1]	$ 0.36	$ 0.47	$ 0.65	$ 0.84
Diluted per share	[1]	$ 0.35	$ 0.47	$ 0.64	$ 0.83

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