v2.4.0.6

Employee Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Benefit cost	$ 1	$ 1
Common stock shares reserved for future issuance	4.1
Non-U.S. Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Cost or expenses included in compensation and benefit expense	5	3
U.S. Defined Contribution Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cost or expenses included in compensation and benefit expense	1
Percentage of employer contributions	100.00%
Percentage of eligible employee contributions receiving employer contributions	4.00%
Employer retirement contributions [Member]
Defined Benefit Plan Disclosure [Line Items]
Cost or expenses included in compensation and benefit expense	1
Share-based compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Cost or expenses included in compensation and benefit expense	$ 1
Common stock shares reserved for future issuance	3.3
Offering periods for ESPP shares, months	6
Percentage of fair market value of common stock	85.00%
Percentage of discount to employees on purchase of common stock under ESPP	15.00%

X

- Definition

We sponsor a voluntary defined contribution savings plan, or 401(k) Plan, for U.S. employees. Employees are immediately eligible to make contributions to the plan and are also eligible for an employer contribution match at an amount equal to 100.0% of the first 4.0% of eligible employee contributions.

+ References

No definition available.

+ Details

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X

- Definition

Offering periods for ESPP shares, months

+ References

No definition available.

+ Details

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X

- Definition

Our ESPP allows eligible U.S. and non-U.S. employees to purchase a limited number of shares of our common stock at six-month intervals, called offering periods, at 85.0% of the lower of the fair market value on the first or the last day of each offering period. The 15.0% discount given to our employees is included in compensation and benefits expense in the Condensed Consolidated Statements of Income.

+ References

No definition available.

+ Details

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Namespace Prefix:	ndaq_
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Balance Type:	na
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X

- Definition

Percentage that employer matches of the employee first 4% of eligible contributions.

+ References

No definition available.

+ Details

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Namespace Prefix:	ndaq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Our ESPP allows eligible U.S. and non-U.S. employees to purchase a limited number of shares of our common stock at six-month intervals, called offering periods, at 85.0% of the lower of the fair market value on the first or the last day of each offering period. The 15.0% discount given to our employees is included in compensation and benefits expense in the Condensed Consolidated Statements of Income.

+ References

No definition available.

+ Details

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Namespace Prefix:	ndaq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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X

- Details

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X

- Definition

The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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X

- Definition

The amount of pension and other (such as medical, dental and life insurance) postretirement benefit costs recognized during the period for (1) defined benefit plans (periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss) on assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments) and for (2) defined contribution plans (to the extent that a plan's defined contributions to an individual's account are to be made for periods in which that individual renders services, the net cost for a period is the contribution called for in that period; if a plan calls for contributions for periods after an individual retires or terminates, the estimated cost is accrued during the employee's service period).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942



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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585



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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5, 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.4)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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