Fair Value Of Financial Instruments (Schedule Of Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2011		Dec. 31, 2010		Sep. 30, 2011 Trading Securities [Member]	Dec. 31, 2010 Trading Securities [Member]	Sep. 30, 2011 Restricted Assets [Member]	Dec. 31, 2010 Restricted Assets [Member]	Sep. 30, 2011 Investment In Dubai Financial Market PJSC [Member]	Dec. 31, 2010 Investment In Dubai Financial Market PJSC [Member]	May 31, 2010 Investment In Dubai Financial Market PJSC [Member] NASDAQ Dubai [Member]	Sep. 30, 2011 Fair Value, Inputs, Level 1 [Member]		Dec. 31, 2010 Fair Value, Inputs, Level 1 [Member]		Sep. 30, 2011 Fair Value, Inputs, Level 2 [Member]		Dec. 31, 2010 Fair Value, Inputs, Level 2 [Member]		Sep. 30, 2011 Fair Value, Inputs, Level 3 [Member]		Dec. 31, 2010 Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative positions, at fair value	$ 1,423	[1]	$ 4,037	[1]												$ 1,423	[1]	$ 4,037	[1]		[1]		[1]
Financial investments, at fair value	294	[2]	253	[2]	270	220	212	190	24	33		294	[2]	253	[2]						[2]		[2]
Financial Assets Measured at Fair Value on a Recurring Basis	1,717		4,290									294		253		1,423		4,037
Derivative positions, at fair value	1,423	[1]	4,037	[1]												1,423	[1]	4,037	[1]		[1]		[1]
Financial Liabilities Measured at Fair Value on a Recurring Basis	1,423		4,037													1,423		4,037
Swedish government debt securities	$ 270		$ 220
Investment owned, percent of net assets											1.00%

[1] Represents net amounts associated with our clearing operations in the derivative markets with NASDAQ OMX Commodities and NASDAQ OMX Stockholm. Receivables and payables attributable to outstanding derivative positions have been netted to the extent that such a legal offset right exists and, at the same time, that it is our intention to settle these items. See "Derivative Positions, at Fair Value" below for further discussion.

[2] Primarily comprised of trading securities, mainly Swedish government debt securities, of $270 million as of September 30, 2011 and $220 million as of December 31, 2010. Of these securities, $212 million as of September 30, 2011 and $190 million as of December 31, 2010 are restricted assets to meet regulatory capital requirements primarily for NASDAQ OMX Stockholm's clearing operations. This balance also includes our 1% available-for-sale investment security in DFM of $24 million as of September 30, 2011 and $33 million as of December 31, 2010. See Note 6, "Investments," for further discussion of our trading investment securities and available-for-sale investment security.