Collateralized Transactions - Collateral Pledged (Details) - USD ($) $ in Thousands	Aug. 31, 2019	Nov. 30, 2018
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	$ 2,182,865	$ 1,838,688
Repurchase Agreements	21,323,082	17,193,486
Total	23,505,947	19,032,174
Corporate equity securities
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	1,952,304	1,505,218
Repurchase Agreements	147,845	487,124
Total	2,100,149	1,992,342
Corporate debt securities
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	174,936	333,221
Repurchase Agreements	1,946,659	1,853,309
Total	2,121,595	2,186,530
Mortgage- and asset-backed securities
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0	249
Repurchase Agreements	2,041,563	2,820,543
Total	2,041,563	2,820,792
U.S. government and federal agency securities
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	55,625	0
Repurchase Agreements	13,423,223	8,181,947
Total	13,478,848	8,181,947
Municipal securities
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	429,925	604,274
Total	429,925	604,274
Sovereign obligations
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	2,433,727	2,945,521
Total	2,433,727	2,945,521
Loans and other receivables
Transfer Of Certain Financial Assets Accounted For As Secured Borrowings [Line Items]
Securities Lending Arrangements	0	0
Repurchase Agreements	900,140	300,768
Total	$ 900,140	$ 300,768