Acquisitions (Results of Operations on Acquisition Included Consolidated Financial Statements) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Diluted	$ 0.35	[1]	$ (1.65)	[1]	$ 0.90	[1]	$ (0.82)	[1]
Thomas Weisel Partners Group Inc [Member]
Total net revenues							$ 1,071,055
Net loss							$ (107,174)
Basic							$ (2.24)
Diluted							$ (2.24)

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