Insurance Subsidiaries - Statutory Equity and Income (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) subsidiary	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Insurance [Abstract]
Number of insurance subsidiaries | subsidiary	3
Voya Retirement Insurance and Annuity Company (VRIAC) (CT) | Connecticut
Statutory Accounting Practices [Line Items]
Statutory Net Income (Loss)	$ 325	$ 377	$ 195
Statutory Capital and Surplus	2,005	2,000
Security Life of Denver Insurance Company (CO) | Colorado
Statutory Accounting Practices [Line Items]
Statutory Net Income (Loss)	(226)	(62)	58
Statutory Capital and Surplus	881	965
ReliaStar Life Insurance Company (RLI) (MN) | Minnesota
Statutory Accounting Practices [Line Items]
Statutory Net Income (Loss)	35	101	234
Statutory Capital and Surplus	$ 1,536	$ 1,633
Voya Insurance and Annuity Company (VIAC) (IA) | Iowa
Statutory Accounting Practices [Line Items]
Statutory Net Income (Loss)			$ 514