Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013 item	Sep. 30, 2013
Restructuring
Number of employees impacted		150
Restructuring charges
Cash charges	$ 4,156		$ 38,339
Non-cash charges	588		12,491
Restructuring expenses - Total:	4,744		50,830
Investment Banking
Restructuring charges
Cash charges	70		1,749
Non-cash charges			3,186
Investment Banking | Severance compensation
Restructuring charges
Cash charges			1,417
Investment Banking | Third party vendor contracts and other costs
Restructuring charges
Cash charges	70		332
Investment Banking | Intangible asset impairment
Restructuring charges
Non-cash charges			2,932
Investment Banking | Stock-based compensation vesting
Restructuring charges
Non-cash charges			254
Fixed Income businesses
Restructuring charges
Cash charges	753		14,457
Non-cash charges			4,069
Fixed Income businesses | Severance compensation
Restructuring charges
Cash charges	262		8,323
Fixed Income businesses | Third party vendor contracts and other costs
Restructuring charges
Cash charges	491		6,134
Fixed Income businesses | Stock-based compensation vesting
Restructuring charges
Non-cash charges			3,681
Fixed Income businesses | Goodwill & intangible asset impairment
Restructuring charges
Non-cash charges			388
ClearPoint
Restructuring charges
Cash charges	88		1,464
Non-cash charges			1,035
ClearPoint | Severance compensation
Restructuring charges
Cash charges			1,263
ClearPoint | Third party vendor contracts and other costs
Restructuring charges
Cash charges	88		201
ClearPoint | Intangible asset impairment
Restructuring charges
Non-cash charges			587
ClearPoint | Deferred compensation and other charges
Restructuring charges
Non-cash charges			448
Other
Restructuring charges
Cash charges	3,245		20,669
Non-cash charges	588		4,201
Other | Severance compensation
Restructuring charges
Cash charges	43		712
Other | Reserve for lease commitments
Restructuring charges
Cash charges	3,202		19,957
Other | Stock-based compensation vesting
Restructuring charges
Non-cash charges	57		195
Other | Impairment of fixed assets and leasehold improvements
Restructuring charges
Non-cash charges	$ 531		$ 4,006