Financing Agreements - Additional Information (Detail) - USD ($)						1 Months Ended	12 Months Ended
	Jan. 23, 2018	Jan. 16, 2018	Jul. 05, 2017	Mar. 17, 2015	May 16, 2013	Nov. 30, 2012	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 24, 2018	Jul. 12, 2017	Jun. 13, 2016	May 06, 2016	Feb. 14, 2014	Jul. 26, 2013	Feb. 11, 2013	Jul. 13, 2012	Jun. 16, 2007
Debt Instrument [Line Items]
Period delinquent payment must be cured to avoid put option				30 days
Minimum net worth required for compliance				$ 3,000,000,000
Long-term debt							$ 3,460,000,000	$ 3,550,000,000
Capacity							6,872,000,000
Payments of financing costs							50,000,000	46,000,000	$ 89,000,000
Credit facility, outstanding							3,197,000,000
Business agreement, term of agreement				10 years
Put option agreement, face amount				$ 500,000,000
ING Group
Debt Instrument [Line Items]
Guarantor obligations, current value								426,000,000
Senior Notes
Debt Instrument [Line Items]
Annual interest rate on loan				1.875%
Revolving Credit Agreement
Debt Instrument [Line Items]
Credit facility, outstanding							$ 0
Debentures | Interest expense
Debt Instrument [Line Items]
Loss related to early extinguishment of debt								$ (17,000,000)
7.25% Voya Holdings Inc. debentures, due 2023(1) | Debentures
Debt Instrument [Line Items]
Annual interest rate on loan							7.25%	7.25%
Debt repayments								$ 17,000,000
Long-term debt							$ 143,000,000	$ 143,000,000
7.63% Voya Holdings Inc. debentures, due 2026(1) | Debentures
Debt Instrument [Line Items]
Annual interest rate on loan							7.63%	7.63%
Debt repayments								$ 16,000,000
Long-term debt							$ 186,000,000	$ 186,000,000
5.5% Senior Notes, due 2022 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued																	$ 850,000,000
Annual interest rate on loan							5.50%	5.50%									5.50%
Debt repayments								$ 487,000,000
Long-term debt							$ 361,000,000	$ 361,000,000
2.9% Senior Notes, due 2018
Debt Instrument [Line Items]
Annual interest rate on loan							2.90%	2.90%
2.9% Senior Notes, due 2018 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued							$ 337,000,000									$ 1,000,000,000
Annual interest rate on loan							2.90%	2.90%								2.90%
Debt repayments							$ 90,000,000	$ 173,000,000
Debt Instrument, Repurchase Amount											$ 400,000,000
Long-term debt							337,000,000	825,000,000
2.9% Senior Notes, due 2018 | Senior Notes | Interest expense
Debt Instrument [Line Items]
Loss related to early extinguishment of debt							(4,000,000)
Five Point Five Percent Senior Notes, due 2022 and Two Point Nine Percent Senior Notes, due 2018 | Senior Notes | Interest expense
Debt Instrument [Line Items]
Loss related to early extinguishment of debt								$ (88,000,000)
Voya Holdings Debentures
Debt Instrument [Line Items]
Long-term debt							$ 426,000,000
6.97% Voya Holdings Inc. debentures, due 2036(1) | Debentures
Debt Instrument [Line Items]
Annual interest rate on loan							6.97%	6.97%
Debt repayments								$ 15,000,000
Long-term debt							$ 94,000,000	$ 94,000,000
1.00% Windsor Property Loan
Debt Instrument [Line Items]
debt instrument, default penalty, percentage							2.50%
Cash collateral balance required or remaining							$ 5,000,000
1.00% Windsor Property Loan | Loans Payable
Debt Instrument [Line Items]
Amount of unsecured notes issued																		$ 10,000,000
Annual interest rate on loan							1.00%	1.00%
Letter of credit, security provided as repayment of notes payable						$ 11,000,000
Long-term debt							$ 5,000,000	$ 5,000,000
5.7% Senior Notes, due 2043 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued															$ 400,000,000
Annual interest rate on loan							5.70%	5.70%							5.70%
Long-term debt							$ 395,000,000	$ 394,000,000
Pre-Capitalized Trust | Senior Notes
Debt Instrument [Line Items]
Annual interest rate on loan				3.976%
3.65% Senior Notes, due 2026 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued												$ 500,000,000
Annual interest rate on loan							3.65%	3.65%				3.65%
Long-term debt							$ 495,000,000	$ 494,000,000
4.8% Senior Notes, due 2046 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued												$ 300,000,000
Annual interest rate on loan							4.80%	4.80%				4.80%
Long-term debt							$ 296,000,000	$ 296,000,000
3.125% Senior Notes, due 2024 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued			$ 400,000,000
Annual interest rate on loan			3.125%				3.125%	0.00%
Proceeds from Issuance of Senior Long-term Debt			$ 395,000,000
Long-term debt							$ 396,000,000	$ 0
5.65% Fixed-to-Floating Rate Junior Subordinated Notes, due 2053 | Junior Subordinated Notes (2053 Notes)
Debt Instrument [Line Items]
Amount of unsecured notes issued					$ 750,000,000
Annual interest rate on loan					5.65%		5.65%	5.65%
Long-term debt							$ 738,000,000	$ 738,000,000
Description of variable rate basis							LIBOR
Basis spread					3.58%
Aggregate principal amount to remain outstanding after effect of redemption							$ 25,000,000
Aetna Notes | Voya Holdings Debentures
Debt Instrument [Line Items]
Minimum principal outstanding in year one							200,000,000
Minimum principal outstanding in year two							100,000,000
Minimum principal outstanding in year three							0
Cash collateral balance required or remaining							231,000,000	127,000,000
Cash collateral deposited for debt							$ 104,000,000	50,000,000
Aetna Notes | Voya Holdings Debentures | Minimum
Debt Instrument [Line Items]
Quarterly fee to guarantor of notes if minimum principal balance is not met							0.75%
Cash collateral balance required or remaining							$ 226,000,000	$ 127,000,000
Aetna Notes | Voya Holdings Debentures | Maximum
Debt Instrument [Line Items]
Quarterly fee to guarantor of notes if minimum principal balance is not met							1.25%
Unsecured and Uncommitted
Debt Instrument [Line Items]
Capacity							$ 496,000,000
Credit facility, outstanding							214,000,000
Revolving Credit Agreement
Debt Instrument [Line Items]
Capacity													$ 2,250,000,000	$ 3,000,000,000
Credit facility, sublimit, maximum borrowing capacity							750,000,000
Unsecured and Committed
Debt Instrument [Line Items]
Capacity							6,171,000,000
Credit facility, outstanding							2,787,000,000
Secured facilities
Debt Instrument [Line Items]
Capacity							205,000,000
Credit facility, outstanding							$ 196,000,000
Subsequent event | 7.63% Voya Holdings Inc. debentures, due 2026(1) | Debentures
Debt Instrument [Line Items]
Debt Instrument, Repurchase Amount		$ 10,000,000
Subsequent event | 7.63% Voya Holdings Inc. debentures, due 2026(1) | Debentures | Interest expense
Debt Instrument [Line Items]
Loss related to early extinguishment of debt		$ (3,000,000)
Subsequent event | 4.7% Fixed-to-Floating Rate Junior Subordinated Notes, due 2048 | Junior Subordinated Notes (2053 Notes)
Debt Instrument [Line Items]
Amount of unsecured notes issued	$ 350,000,000
Annual interest rate on loan	4.70%
Description of variable rate basis	LIBOR
Basis spread	2.084%
Aggregate principal amount to remain outstanding after effect of redemption	$ 25,000,000
Subsequent event | Revolving Credit Agreement
Debt Instrument [Line Items]
Minimum net worth required for compliance										$ 6,000,000,000
Capacity										$ 1,250,000,000