Commitments and Contingencies - Additional Information (Detail) £ in Millions, $ in Millions				1 Months Ended
	Sep. 11, 2019 USD ($)	Feb. 25, 2019 GBP (£)	Nov. 15, 2018 GBP (£)	Jan. 31, 2019 USD ($)	Dec. 31, 2017 GBP (£) Company	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Indemnity limit | £					£ 28
Number of insurance company sold | Company					2
Commitment to fund limited partnership investments						$ 1,009
Commitment to fund U.S. commercial mortgage loan investments						24
Commitment to fund private placement investments						79
Updated Indemnity Limit | £		£ 265	£ 237
Loss Contingency, Damages Sought				$ 5
Loss contingencies actions by plaintiff	On September 11, 2019, plaintiffs filed a renewed motion seeking the same relief from their August 7, 2019 motion with an exception that allows GFIH to transfer $450 million of expected proceeds from the sale of Genworth Canada through a dividend to Genworth Holdings to allow the pay off of a senior secured term loan facility dated March 7, 2018 among Genworth Holdings as the borrower, GFIH as the limited guarantor and the lending parties thereto. Oral arguments on our motion to dismiss and plaintiffs’ motion occurred on October 21, 2019. We intend to continue to vigorously defend this action.
Restricted Cash Proceeds On Sale Per Litigation	$ 450
Notional amount
Commitments and Contingencies Disclosure [Line Items]
Commitment to fund bank loan investments						$ 51	$ 33