Variable Interest Entities (Assets And Liabilities Of Consolidated VIEs) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Cash	$ 3,030,936	$ 3,638,648	$ 3,491,032	$ 4,276,775
Financial instruments owned	16,949,647	18,500,445
Securities purchased under agreement to resell	3,238,189	3,854,746
Receivables	4,397,127	3,830,967
Loans to and investments in associated companies	1,737,337	1,757,369
Other	1,841,240	1,473,464
Total	45,041,927	46,331,184
Other secured financings	973,619	908,741
Long-term debt	7,169,813	7,400,582
Total liabilities	34,418,582	35,548,661
Noncontrolling interests	178,040	64,679
Securitization Vehicles [Member]
Variable Interest Entity [Line Items]
Cash	4,600	1,100
Financial instruments owned	79,000	68,300
Securities purchased under agreement to resell	672,500	717,300
Aircraft	0	0
Receivables	337,100	149,800
Loans to and investments in associated companies	0	0
Other	17,700	8,800
Total	1,110,900	945,300
Other secured financings	1,084,300	930,800
Long-term debt	0	0
Other	26,000	14,500
Total liabilities	1,110,300	945,300
Noncontrolling interests	0	0
Real Estate Investment Vehicles [Member]
Variable Interest Entity [Line Items]
Cash	1,900
Financial instruments owned	0
Securities purchased under agreement to resell	0
Aircraft	0
Receivables	126,100
Loans to and investments in associated companies	106,400
Other	9,200
Total	243,600
Other secured financings	0
Long-term debt	104,500
Other	3,400
Total liabilities	107,900
Noncontrolling interests	82,700
Airplane Financing Vehicle [Member]
Variable Interest Entity [Line Items]
Cash	0
Financial instruments owned	0
Securities purchased under agreement to resell	0
Aircraft	27,000
Receivables	0
Loans to and investments in associated companies	0
Other	0
Total	27,000
Other secured financings	0
Long-term debt	21,600
Other	4,500
Total liabilities	26,100
Noncontrolling interests	0
Jefferies [Member]
Variable Interest Entity [Line Items]
Secured financings eliminated in consolidation	$ 246,600	$ 22,100