Discontinued Operations - Summary of Liabilities Related to Discontinued Operations (Parenthetical) (Detail) £ in Millions, $ in Millions, $ in Millions	Sep. 21, 2021 USD ($)	Sep. 21, 2021 GBP (£)	Mar. 03, 2021 AUD ($)	Mar. 03, 2021 USD ($)	Mar. 03, 2021 GBP (£)
Genworth Mortgage Insurance Australia Limited [Member]
Income Statement, Balance Sheet and Additional Disclosures by Planned Disposal Groups [Line Items]
Proceeds from sale of disposal group including discontinuing operations			$ 483	$ 370
Mandatory Payment [Member] | Promissory Note [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Planned Disposal Groups [Line Items]
Promissory Note repayment	$ 296	£ 215
AXA Settlement Agreement Promissory Note [Member] | Mandatory Payment [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Planned Disposal Groups [Line Items]
Promissory Note repayment				$ 245	£ 176