Aggregate carrying amount of the estimated litigation liability for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.25)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LitigationReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Contingencies (Details) (USD $) In Millions, unless otherwise specified			9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Fifth Market 2008 claim patents	Sep. 30, 2012 Realtime Data 2009 claim patents lawsuits	Sep. 30, 2012 MF Global Bankruptcy Litigation [Member]
Number of alledged patent infringements (in patents)			2	4
Number of additional related lawsuits (in lawsuits)				2
Dropped Patents				3
Asserted Patents				6
Percentage of return of funds to account holders					100.00%
Accrued liability related to all outstanding legal matters	$ 13.3	$ 12.8