Investments - Allowance for Loan Losses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Impaired Financing Receivable, Unpaid Principal Balance, Equal to or Greater than 90 Days Past Due	$ 0	$ 5.1
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	5.1
Collective valuation allowance for losses, beginning of period	3.8	3.9
Addition to/(release of) allowance for losses	(0.4)	(0.1)
Collective valuation allowance for losses, end of period	$ 3.4	$ 3.8

Impaired Financing Receivable, Unpaid Principal Balance, Equal to or Greater than 90 Days Past Due

No definition available.

Name:	ingus_ImpairedFinancingReceivableUnpaidPrincipalBalanceEqualToOrGreaterThan90DaysPastDue
Namespace Prefix:	ingus_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953423-111524

+ Details

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

- Definition

The increase (decrease) in the allowance for credit losses related to financing receivables.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953423-111524

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Financing receivables that are equal to or greater than 90 days past due.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7A

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953401-111524

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Details

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