Investments - OTTI (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2015 USD ($) securities	Jun. 30, 2014 USD ($) securities	Jun. 30, 2015 USD ($) securities	Jun. 30, 2014 USD ($) securities
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	19	18	26	24
Impairment	$ 2.4	$ 1.4	$ 4.3	$ 2.3
U.S. corporate public securities
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	0	0	0	1
Impairment	$ 0.0	$ 0.0	$ 0.0	$ 0.1
Foreign corporate public securities and foreign governments
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	2	5	2	5
Impairment	$ 1.8	$ 1.2	$ 2.3	$ 1.2
Foreign corporate private securities
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	1	0	1	0
Impairment	$ 0.5	$ 0.0	$ 0.5	$ 0.0
Residential mortgage-backed
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	16	12	23	15
Impairment	$ 0.1	$ 0.2	$ 1.5	$ 0.9
Commercial mortgage-backed
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	0	0	0	2
Impairment	$ 0.0	$ 0.0	$ 0.0	$ 0.1
Other asset-backed securities
Available-for-sale Securities Including Securities Pledged [Line Items]
No. of Securities \| securities	0	1	0	1
Impairment	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Intent related impairment
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.2	$ 1.3	$ 1.2	$ 1.4
No. of Securities \| securities	2	7	4	9
Intent related impairment \| U.S. corporate public securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.0	$ 0.0	$ 0.0	$ 0.0
No. of Securities \| securities	0	0	0	0
Intent related impairment \| Foreign corporate public securities and foreign governments
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.2	$ 1.2	$ 0.7	$ 1.2
No. of Securities \| securities	1	5	1	5
Intent related impairment \| Foreign corporate private securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.0	$ 0.0	$ 0.0	$ 0.0
No. of Securities \| securities	0	0	0	0
Intent related impairment \| Residential mortgage-backed
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.0	$ 0.1	$ 0.5	$ 0.1
No. of Securities \| securities	1	2	3	2
Intent related impairment \| Commercial mortgage-backed
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.0	$ 0.0	$ 0.0	$ 0.1
No. of Securities \| securities	0	0	0	2
Intent related impairment \| Other asset-backed securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-down related to intent impairments	$ 0.0	$ 0.0	$ 0.0	$ 0.0
No. of Securities \| securities	0	0	0	0
Credit related impairment
Available-for-sale Securities Including Securities Pledged [Line Items]
Write-downs related to credit impairments	$ 2.2	$ 0.1	$ 3.1	$ 0.9

The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8B

-URI http://asc.fasb.org/extlink&oid=27724398&loc=SL6284393-111563

+ Details

Name:	us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

+ Details

Name:	us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Available-for-sale Securities, Including Securities Pledged [Line Items]

+ References

No definition available.

+ Details

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

- Definition

Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Intent Impairments, Available-for-sale Securities

+ References

No definition available.

+ Details

Name:	voya_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsIntentImpairmentsAvailableForSaleSecurities
Namespace Prefix:	voya_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Number of Securities

+ References

No definition available.

+ Details

Name:	voya_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNumberOfSecurities
Namespace Prefix:	voya_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=voya_U.S.CorporatePublicSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=voya_ForeignCorporatePublicSecuritiesandForeignGovernmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=voya_ForeignCorporatePrivateSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=voya_OtherAssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	voya_OtherThanTemporaryImpairmentTypeAxis=voya_OtherThanTemporaryImpairmentIntentRelatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	voya_OtherThanTemporaryImpairmentTypeAxis=voya_OtherThanTemporaryImpairmentCreditRelatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: