Segments - Operating Revenues (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Sales Information [Line Items]
Investment management intersegment revenues	$ 4,188.0	$ 4,234.1	$ 8,406.4	$ 8,376.5	$ 8,106.8
Closed Block Variable Annuity	(504.3)	(180.6)	(70.0)	794.9	677.7
Net realized investment gains (losses) and related charges and adjustments	(11.5)	300.5	603.4	219.2	47.7
Gain (loss) on change in fair value of derivatives related to guaranteed benefits	90.7	68.8	83.1	(399.0)	(66.9)
Revenues related to businesses exited through reinsurance or divestment	(67.9)	35.8	64.6	116.1	137.6
Revenues (loss) attributable to noncontrolling interests	101.2	284.1	313.8	399.1	143.2
Other adjustments to operating revenues	163.0	104.5	214.0	212.0	228.1
Total revenues	3,959.2	4,847.2	9,615.3	9,718.8	9,274.2
Intersegment Eliminations
Sales Information [Line Items]
Investment management intersegment revenues	79.2	78.5	157.6	164.1	156.8
Retirement Solutions \| Retirement
Sales Information [Line Items]
Investment management intersegment revenues	1,180.1	1,119.3	2,271.9	2,225.4	2,179.0
Retirement Solutions \| Annuities
Sales Information [Line Items]
Investment management intersegment revenues	611.6	679.9	1,307.0	1,401.4	1,482.5
Investment Management
Sales Information [Line Items]
Investment management intersegment revenues	280.5	260.8	545.5	491.9	454.5
Insurance Solutions \| Individual Life
Sales Information [Line Items]
Investment management intersegment revenues	1,381.9	1,421.2	2,793.9	2,785.0	2,613.4
Insurance Solutions \| Employee Benefits
Sales Information [Line Items]
Investment management intersegment revenues	629.8	627.1	1,251.2	1,246.2	1,277.8
Total Ongoing Businesses
Sales Information [Line Items]
Investment management intersegment revenues	4,083.9	4,108.3	8,169.5	8,149.9	8,007.2
Corporate
Sales Information [Line Items]
Investment management intersegment revenues	25.0	33.5	65.9	(13.7)	(132.3)
Closed Blocks
Sales Information [Line Items]
Investment management intersegment revenues	79.1	92.3	171.0	240.3	231.9
Closed Blocks \| Closed Block Institutional Spread Products
Sales Information [Line Items]
Investment management intersegment revenues	64.6	73.3	127.2	188.1	167.6
Closed Blocks \| Closed Block Other
Sales Information [Line Items]
Investment management intersegment revenues	$ 14.5	$ 19.0	$ 43.8	$ 52.2	$ 64.3

Overall income (loss) from a disposal group that is classified as a component of the entity, before income tax, reported as a separate component of income before extraordinary items. Includes the following (before income tax): income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e957-107759

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.12)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 05

-Paragraph 15

-Article 3

+ Details

Name:	us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fees and other service revenues recognized in the period that are not otherwise specified in the taxonomy.

+ References

+ Details

Name:	us-gaap_RevenueOtherFinancialServices
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

+ Details

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Revenue (Loss), Attributable to Noncontrolling Interest

+ References

No definition available.

+ Details

Name:	voya_RevenueLossAttributableToNoncontrollingInterest
Namespace Prefix:	voya_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Revenue (Loss), Closed Block Variable Annuity

+ References

No definition available.

+ Details

Name:	voya_RevenueLossClosedBlockVariableAnnuity
Namespace Prefix:	voya_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Revenue, Net Realized Investment Gain (Loss) and Related Charges and Adjustments

+ References

No definition available.

+ Details

Name:	voya_RevenueNetRealizedInvestmentGainLossAndRelatedChargesAndAdjustments
Namespace Prefix:	voya_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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