v2.4.0.6
Clearing Operations (Narrative) (Details) (USD $)
 3 Months Ended
Mar. 31, 2013
contract
Dec. 31, 2012
Mar. 31, 2012
contract
Clearing Operations [Line Items]      
Financial investments, at fair value $ 218,000,000 [1] $ 223,000,000 [1]  
Market value of derivative contracts outstanding, prior to netting 1,448,000,000    
Total number of derivative contracts cleared through NOS Clearing 27,882,196   30,687,619
Restricted cash 83,000,000 85,000,000  
Default Fund Contributions 229,000,000    
NASDAQ OMX Nordic [Member]
      
Clearing Operations [Line Items]      
Financial investments, at fair value 121,000,000    
Credit facility, borrowing capacity 92,000,000    
Committed amount of credit facility toward regulatory requirements 11,000,000    
Clearing members pledged margin collateral 6,000,000,000 6,300,000,000  
Contract value of resale and repurchase agreements 4,700,000,000   4,400,000,000
Total number of derivative contracts cleared 1,190,292   865,359
Power of assessment of the clearing member's contribution to the financial markets and commodities markets default funds 100.00%    
Liability Waterfall [Member]
      
Clearing Operations [Line Items]      
Junior capital, cash deposits and pledged assets 15,000,000    
Senior capital, cash deposits and pledged assets 23,000,000    
NOS Clearing [Member]
      
Clearing Operations [Line Items]      
Total number of derivative contracts cleared 605,090    
Market value of derivative contracts outstanding, prior to netting 22,000,000    
Default Fund Contributions 42,000,000    
Pledged default fund contributions and margin collateral 399,000,000    
NOCC [Member]
      
Clearing Operations [Line Items]      
Cash collateral for borrowed securities 38,000,000 33,000,000  
Aggregate amount of letters of credit 84,000,000 101,000,000  
NOCC guarantee fund [Member]
      
Clearing Operations [Line Items]      
Contribution to guarantee fund $ 25,000,000 $ 25,000,000  
[1] Primarily comprised of trading securities, mainly Swedish government debt securities, of $195 million as of March 31, 2013 and $201 million as of December 31, 2012. Of these securities, $141 million as of March 31, 2013 and $134 million as of December 31, 2012 are restricted assets to meet regulatory capital requirements primarily for clearing operations at NASDAQ OMX Nordic Clearing. This balance also includes our available-for-sale investment security in DFM valued at $23 million as of March 31, 2013 and $22 million as of December 31, 2012. See Note 6, “Investments,” for further discussion of our trading investment securities and available-for-sale investment security.