Schedule II - Condensed Financial Information of Parent - Loans to Subsidiaries (Details) - Parent Issuer - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income, operating	$ 8	$ 9	$ 5
Loans to subsidiaries	$ 191	$ 278
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan to subsidiary, reciprocal interest rate	2.00%	2.00%
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan to subsidiary, reciprocal interest rate	5.00%	5.00%
Voya Alternative Asset Management LLC | Subsidiary Loan, Due June 30, 2018, (4.65) Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 2	$ 2
Rate	(4.64%)	(4.64%)
Voya Institutional Plan Services, LLC | Subsidiary Loan, Due January 2, 2018, 2.42 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 20	$ 1
Rate	2.42%	2.42%
Voya Institutional Plan Services, LLC | Subsidiary Loan, Due January 3, 2018, 2.45 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 34	$ 14
Rate	2.45%	2.45%
Voya Institutional Plan Services, LLC | Subsidiary Loan, Due January 4, 2018, 2.46 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 5	$ 17
Rate	2.46%	2.46%
Voya Institutional Plan Services, LLC | Subsidiary Loan, Due January 9, 2018, 2.52 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 1	$ 10
Rate	2.52%	2.52%
Voya Institutional Plan Services, LLC | Subsidiary Loan, Due January 11, 2018, 2.53 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 5	$ 1
Rate	2.53%	2.53%
Voya Institutional Plan Services, LLC | Subsidiary Loan, Due January 12, 2018, 2.53 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 4	$ 0
Rate	2.53%	2.53%
Voya Capital | Subsidiary Loan, Due January 4 2018, 2.49 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 1	$ 3
Rate	2.49%	2.49%
Voya Investment Management, LLC | Subsidiary Loan, Due January 29, 2018, 2.57 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 51	$ 15
Rate	2.57%	2.57%
Voya Payroll Management, Inc. | Subsidiary Loan, Due July 3, 2017, 2.17 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 0	$ 4
Rate	2.17%	2.17%
Voya Holdings Inc. | Subsidiary Loan, Due January 29, 2018, 2.57 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 68	$ 203
Rate	2.57%	2.57%
Voya Holdings Inc. | Subsidiary Loan, Due January 26, 2017, 2.39 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 0	$ 2
Rate	2.39%	2.39%
Voya Holdings Inc. | Subsidiary Loan, Due January 27, 2017, 2.40 Percent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to subsidiaries	$ 0	$ 6
Rate	2.40%	2.40%