Fair Value of Financial Instruments (Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Additional Information) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial investments, at fair value	$ 197	[1]	$ 189	[1]
Default funds and margin deposits	2,253		1,961
Restricted assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial investments, at fair value	177		167
Reverse Repurchase Agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Default funds and margin deposits	1,501		1,093
US Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Default funds and margin deposits	$ 710		$ 774

[1] As of March 31, 2014 and December 31, 2013, Level 1 financial investments, at fair value were primarily comprised of trading securities, mainly Swedish government debt securities. Of these securities, $177 million as of March 31, 2014 and $167 million as of December 31, 2013 are assets utilized to meet regulatory capital requirements primarily for clearing operations at NASDAQ OMX Nordic Clearing.