Financing Agreements - Credit Facilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Nov. 01, 2019
Line of Credit Facility [Line Items]
Capacity	$ 5,036.0
Utilization	3,857.0
Unused Commitment	928.0
Revolving Credit Agreement
Line of Credit Facility [Line Items]
Capacity		$ 500.0
Minimum net worth required for compliance		$ 6,150.0
Security Life of Denver International Limited \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	61.0
Utilization	51.0
Unused Commitment	10.0
Voya Financial, Inc. \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	500.0
Utilization	0.0
Unused Commitment	500.0
Voya Financial, Inc. / Security Life of Denver International Limited \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	250.0
Utilization	242.0
Unused Commitment	8.0
Voya Financial, Inc. / Security Life of Denver International Limited \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	475.0
Utilization	475.0
Unused Commitment	0.0
Voya Financial, Inc. / Security Life of Denver International Limited \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	1,725.0
Utilization	1,606.0
Unused Commitment	119.0
Voya Financial, Inc. \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	300.0
Utilization	300.0
Unused Commitment	0.0
Voya Financial, Inc. \| Secured facilities
Line of Credit Facility [Line Items]
Capacity	10.0
Utilization	1.0
Unused Commitment	0.0
Voya Financial, Inc. / Roaring River LLC \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	425.0
Utilization	392.0
Unused Commitment	33.0
Voya Financial, Inc. / Roaring River IV, LLC \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	565.0
Utilization	357.0
Unused Commitment	208.0
Voya Financial, Inc. / Security Life of Denver International Limited \| Unsecured and Uncommitted
Line of Credit Facility [Line Items]
Capacity	300.0
Utilization	58.0
Unused Commitment	0.0
Voya Financial, Inc. \| Unsecured and Committed
Line of Credit Facility [Line Items]
Capacity	300.0
Utilization	250.0
Unused Commitment	50.0
Voya Financial, Inc. \| Unsecured and Uncommitted
Line of Credit Facility [Line Items]
Capacity	125.0
Utilization	125.0
Unused Commitment	0.0
Revolving Credit Agreement
Line of Credit Facility [Line Items]
Utilization	0.0
Amounts of LOCs outstanding	$ 0.0

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The lowest amount of net worth (total assets minus total liabilities) required by secondary market investors or state-imposed regulatory mandates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47304-110998

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)(a)
-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47080-110998

+ Details

Name:	us-gaap_MinimumNetWorthRequiredForCompliance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant