Segment Reporting (Schedule of Operating Information, Segment) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net revenues	$ 356,878,000	$ 334,214,000	$ 358,857,000	$ 366,613,000	$ 401,599,000	$ 340,388,000	$ 328,009,000	$ 312,030,000	$ 1,416,562,000	$ 1,382,026,000	$ 1,090,636,000
Income/(loss) before income taxes									138,608,000	(229,000)	120,414,000
Global Wealth Management [Member]
Net revenues									908,158,000.0	843,269,000	595,974,000.0
Income/(loss) before income taxes									235,382,000.0	194,023,000	104,699,000.0
Institutional Group [Member]
Net revenues									507,397,000.0	541,839,000	494,092,000.0
Income/(loss) before income taxes									63,269,000.0	129,535,000	129,133,000.0
Other [Member]
Net revenues									1,007,000.0	(3,082,000)	570,000.0
Income/(loss) before income taxes									$ (160,043,000.0)	$ (323,787,000)	$ (113,418,000.0)