Schedule II - Condensed Financial Information of Parent - Returns of Capital and Dividends (Details) - Parent Issuer - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Return of capital contributions and dividends from subsidiaries	$ 1,093	$ 1,001	$ 1,709
Voya Holdings Inc.
Condensed Financial Statements, Captions [Line Items]
Return of capital contributions and dividends from subsidiaries	1,020	916	1,468
Return of capital contributions and dividends from subsidiaries, noncash	24
Security Life of Denver International Ltd
Condensed Financial Statements, Captions [Line Items]
Return of capital contributions and dividends from subsidiaries	0	30	0
Security Life of Denver Insurance Company
Condensed Financial Statements, Captions [Line Items]
Return of capital contributions and dividends from subsidiaries	73	54	241
Voya Insurance Management (Bermuda), Ltd (2)
Condensed Financial Statements, Captions [Line Items]
Return of capital contributions and dividends from subsidiaries	$ 0	$ 1	$ 0