|
Clearing Operations (Schedule of Clearing Member Default Fund Contributions Additional Information) (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
|
Dec. 31, 2012
|
||||
|---|---|---|---|---|---|---|
| Clearing Operations [Line Items] | ||||||
| Investment of cash contributions in highly rated debt securities | $ 191 | [1] | $ 175 | [1] | ||
|
NASDAQ OMX Nordic [Member]
|
||||||
| Clearing Operations [Line Items] | ||||||
| Investment of cash contributions in highly rated debt securities | $ 73 | |||||
|
||||||