Collateralized Transactions - Contractual Maturity (Details) - USD ($) $ in Thousands	Nov. 30, 2017	Nov. 30, 2016
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities lending arrangements	$ 2,843,911	$ 2,819,132
Repurchase agreements	19,829,249	17,012,332
Obligation to return securities received as collateral	103
Total	22,673,263	19,831,464
Overnight and Continuous
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities lending arrangements	1,676,940	2,131,891
Repurchase agreements	10,780,474	9,147,176
Obligation to return securities received as collateral	103
Total	12,457,517	11,279,067
Up to 30 Days
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities lending arrangements	0	39,673
Repurchase agreements	4,058,228	2,008,119
Obligation to return securities received as collateral	0
Total	4,058,228	2,047,792
31-90 Days
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities lending arrangements	741,971	104,516
Repurchase agreements	3,211,464	3,809,533
Obligation to return securities received as collateral	0
Total	3,953,435	3,914,049
Greater than 90 Days
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities lending arrangements	425,000	543,052
Repurchase agreements	1,779,083	2,047,504
Obligation to return securities received as collateral	0
Total	$ 2,204,083	$ 2,590,556