Financing Agreements - Additional Information (Detail) - USD ($) $ in Millions					12 Months Ended
	Jul. 12, 2019	Jan. 23, 2018	Mar. 17, 2015	May 16, 2013	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 01, 2019	Jul. 05, 2017	Jun. 16, 2007
Debt Instrument [Line Items]
Long-term debt					$ 3,043.0	$ 3,137.0
Payments of financing costs					34.0	34.0	$ 50.0
Business agreement, term of agreement			10 years
Put option agreement, face amount			$ 500.0
Debt securities | Interest expense
Debt Instrument [Line Items]
Income (loss) related to early extinguishment of debt					$ (9.0)	$ (40.0)	$ (4.0)
Senior Notes
Debt Instrument [Line Items]
Annual interest rate on loan			1.875%
Junior Subordinated Notes
Debt Instrument [Line Items]
Maximum deferral period for one or more consecutive interest payments					5 years
3.125% Senior Notes, due 2024 | Senior Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued									$ 400.0
Annual interest rate on loan					3.125%	3.125%			3.125%
Long-term debt					$ 397.0	$ 396.0
2.9% Senior Notes, due 2018 | Senior Notes
Debt Instrument [Line Items]
Annual interest rate on loan					2.90%
5.5% Senior Notes, due 2022 | Senior Notes
Debt Instrument [Line Items]
Annual interest rate on loan					5.50%	5.50%
Repurchase amount						$ 141.0
Repayments of long-term debt	$ 97.0					125.0
Long-term debt					$ 0.0	$ 96.0
5.65% Fixed-to-Floating Rate Junior Subordinated Notes, due 2053 | Junior Subordinated Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued				$ 750.0
Annual interest rate on loan				5.65%	5.65%	5.65%
Description of variable rate basis				LIBOR
Basis spread				3.58%
Long-term debt					$ 739.0	$ 739.0
4.7% Fixed-to-Floating Rate Junior Subordinated Notes, due 2048 | Junior Subordinated Notes
Debt Instrument [Line Items]
Amount of unsecured notes issued		$ 350.0
Annual interest rate on loan		4.70%			4.70%	4.70%
Description of variable rate basis		LIBOR
Basis spread		2.084%
Long-term debt					$ 345.0	$ 344.0
Voya Holdings Debentures | Debentures
Debt Instrument [Line Items]
Long-term debt					$ 358.0	$ 358.0
7.25% Voya Holdings Inc. debentures, due 2023 | Debentures
Debt Instrument [Line Items]
Annual interest rate on loan					7.25%	7.25%
Long-term debt					$ 139.0	$ 138.0
7.63% Voya Holdings Inc. debentures, due 2026 | Debentures
Debt Instrument [Line Items]
Annual interest rate on loan					7.63%	7.63%
Long-term debt					$ 138.0	$ 138.0
6.97% Voya Holdings Inc. debentures, due 2036 | Debentures
Debt Instrument [Line Items]
Annual interest rate on loan					6.97%	6.97%
Long-term debt					$ 79.0	$ 79.0
1.00% Windsor Property Loan
Debt Instrument [Line Items]
Cash collateral balance required or remaining					$ 5.0
1.00% Windsor Property Loan | Loans Payable
Debt Instrument [Line Items]
Amount of unsecured notes issued										$ 10.0
Annual interest rate on loan					1.00%	1.00%
Long-term debt					$ 4.0	$ 5.0
Pre-Capitalized Trust | Senior Notes
Debt Instrument [Line Items]
Annual interest rate on loan			3.976%
Aetna Notes | Voya Holdings Debentures
Debt Instrument [Line Items]
Minimum principal outstanding in year one					$ 0.0
Quarterly fee to guarantor of notes if minimum principal balance is not met					1.25%
Cash collateral balance required or remaining					$ 372.0	267.0
Cash collateral deposited for debt					105.0	36.0
Aetna Notes | Voya Holdings Debentures | Minimum
Debt Instrument [Line Items]
Cash collateral balance required or remaining					$ 358.0	$ 258.0
Revolving Credit Agreement
Debt Instrument [Line Items]
Minimum net worth required for compliance								$ 6,150.0