Commitments, Contingencies and Guarantees (Details Textual) (USD $) In Millions, unless otherwise specified	1 Months Ended		1 Months Ended
	Mar. 09, 2012	Sep. 30, 2012 Letters of Credit [Member]	Jun. 09, 2010 TT [Member]	Feb. 03, 2010 TT [Member]	Aug. 31, 2004 TT [Member]	Aug. 24, 2009 Tullett Liberty [Member] Person	Oct. 31, 2009 Tullett Prebon [Member]	Oct. 22, 2009 Tullett Prebon [Member]	Nov. 30, 2010 Tullett Prebon Information [Member]	Apr. 04, 2011 Tullett subsidiaries [Member]	Aug. 10, 2012 Tullett subsidiaries [Member] Minimum [Member]	Mar. 09, 2012 International Painters [Member]	Apr. 02, 2012 Samuel Pill [Member]	Aug. 24, 2009 BGC Financial [Member] Person
Commitments, Contingencies and Guarantees (Textual) [Abstract]
Name of Plaintiff	International Painters and Allied Trades Industry Pension Fund		Trading Technologies International, Inc. (“TT”)	Trading Technologies International, Inc. (“TT”)	Trading Technologies International, Inc. (“TT”)	Tullett Liberty Securities LLC	Tullett Prebon plc (“Tullett”)					International Painters and Allied Trades Industry Pension Fund	Samuel Pill
Name of defendant									Tullett Prebon Information
Loss contingency, damages			$ 2.5
Loss contingency, compensatory damages						779		1,000			14
Loss contingency, exemplary damages						500
Damages awarded									0.8
Contingent liability under letters of credit		$ 2.0
Lawsuit filing date			June 9, 2010	Feb 3, 2010	Aug, 2004	Aug 24, 2009		Oct 22, 2009	Nov 2010	April 4, 2011		March 9, 2012	April 2, 2012
Number of new employees added						35								79