Acquisition of KBW, Inc. (Results of Operations on Acquisition Included Consolidated Financial Statements) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Acquisition of KBW, Inc.
Total net revenues	$ 470,536	$ 1,436,354	$ 1,369,556
Net income	$ 33,296	$ (16,464)	$ 89,502
Basic	$ 0.55	$ (0.26)	$ 1.47
Diluted	$ 0.46	$ (0.26)	$ 1.23

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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