Acquisitions and Divestiture (Schedule Of Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	5 years		5 years
Purchased intangible assets	$ 16
Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	19 years		21 years
Purchased intangible assets	121
Other [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	8 years		8 years
NOS Clearing [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Purchased intangible assets	1	[1]
BWise [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Purchased intangible assets	35
BWise [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Purchased intangible assets	7
BWise [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Purchased intangible assets	23
eSpeed [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Purchased intangible assets	715
eSpeed [Member] | Trade names [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets Acquired	578
eSpeed [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	5 years
Finite-lived Intangible Assets Acquired	16
eSpeed [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	13 years
Finite-lived Intangible Assets Acquired	121
eSpeed [Member] | Market Services [Member] | Trade names [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets Acquired	528
eSpeed [Member] | Market Services [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	5 years
Finite-lived Intangible Assets Acquired	14
eSpeed [Member] | Market Services [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	13 years
Finite-lived Intangible Assets Acquired	105
eSpeed [Member] | Information Services [Member] | Trade names [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets Acquired	50
eSpeed [Member] | Information Services [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	5 years
Finite-lived Intangible Assets Acquired	2
eSpeed [Member] | Information Services [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	13 years
Finite-lived Intangible Assets Acquired	16
TR Corporate Solutions Businesses [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Purchased intangible assets	91
TR Corporate Solutions Businesses [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	5 years
Finite-lived Intangible Assets Acquired	2
Purchased intangible assets	2
TR Corporate Solutions Businesses [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	89
Purchased intangible assets	$ 89
Minimum [Member] | TR Corporate Solutions Businesses [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	2 years
Minimum [Member] | TR Corporate Solutions Businesses [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	9 years
Maximum [Member] | TR Corporate Solutions Businesses [Member] | Technology [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	5 years
Maximum [Member] | TR Corporate Solutions Businesses [Member] | Customer relationships [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite Lived Intangible Assets Weighted Average Useful Life	14 years

[1] In the third quarter of 2012, we recognized a gain of $4 million on our acquisition of NOS Clearing, which is included in merger and strategic initiatives expense in the Consolidated Statements of Income.