Investments (excluding Consolidated Investment Entities) - Loans by Debt Service Coverage Ratio (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Benchmark debt service coverage ratio, less than indicates property's operations income is less than debt payments	100.00%	100.00%
Commercial mortgage loans secured by land or construction loans	$ 23	$ 59
Total Commercial mortgage loans	$ 8,689	$ 8,006
Greater than 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Debt Service Coverage Ratio, minimum	150.00%	150.00%
Commercial mortgage loans	$ 7,013	$ 6,421
Greater than 1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Debt Service Coverage Ratio, minimum	125.00%	125.00%
Debt Service Coverage Ratio, maximum	150.00%	150.00%
Commercial mortgage loans	$ 655	$ 824
Greater than 1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Debt Service Coverage Ratio, minimum	100.00%	100.00%
Debt Service Coverage Ratio, maximum	125.00%	125.00%
Commercial mortgage loans	$ 893	$ 597
Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Debt Service Coverage Ratio, maximum	100.00%	100.00%
Commercial mortgage loans	$ 105	$ 105

Amount before allowance of commercial loans to develop land for sale or construction thereon. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5066-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a)(2))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LoansReceivableCommercialDevelopment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allowance of mortgage loans on existing land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5066-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a)(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LoansReceivableCommercialMortgage
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allowance of commercial loans issued to businesses to acquire, develop, construct, improve, or refinance land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(c))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5066-111524

+ Details

Name:	us-gaap_LoansReceivableCommercialRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Loans and Leases Receivable, Debt Service Coverage, Benchmark Ratio

+ References

No definition available.

+ Details

Name:	voya_LoansAndLeasesReceivableDebtServiceCoverageBenchmarkRatio
Namespace Prefix:	voya_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Loans Receivable, Debt Service Coverage Ratio, Maximum

+ References

No definition available.

+ Details

Name:	voya_LoansReceivableDebtServiceCoverageRatioMaximum
Namespace Prefix:	voya_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Loans Receivable, Debt Service Coverage Ratio, Minimum

+ References

No definition available.

+ Details

Name:	voya_LoansReceivableDebtServiceCoverageRatioMinimum
Namespace Prefix:	voya_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Schedule of Loans by Debt Service Coverage Ratio [Line Items]

+ References

No definition available.

+ Details

Name:	voya_ScheduleOfLoansByDebtServiceCoverageRatioLineItems
Namespace Prefix:	voya_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	voya_DebtServiceCoverageRatioRangeAxis=voya_LoansReceivableDebtServiceCoverageRatioRangeOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	voya_DebtServiceCoverageRatioRangeAxis=voya_LoansReceivableDebtServiceCoverageRatioRangeTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	voya_DebtServiceCoverageRatioRangeAxis=voya_LoansReceivableDebtServiceCoverageRatioRangeThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	voya_DebtServiceCoverageRatioRangeAxis=voya_LoansReceivableDebtServiceCoverageRatioRangeFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: