Collateralized Transactions - Collateral Pledged (Details) $ in Thousands	Nov. 30, 2015 USD ($)
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	$ 2,979,300
Repurchase Agreements	20,195,982
Total	23,175,282
Corporate equity securities [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	2,195,912
Repurchase Agreements	275,880
Total	2,471,792
Corporate debt securities [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	748,405
Repurchase Agreements	1,752,222
Total	2,500,627
Mortgage- and asset-backed securities [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0
Repurchase Agreements	3,537,812
Total	3,537,812
U.S. government and federal agency securities [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	34,983
Repurchase Agreements	12,006,081
Total	12,041,064
Municipal securities [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0
Repurchase Agreements	357,350
Total	357,350
Sovereign obligations [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0
Repurchase Agreements	1,804,103
Total	1,804,103
Loans and other receivables [Member]
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0
Repurchase Agreements	462,534
Total	$ 462,534