Derivative Financial Instruments - Remaining Contract Maturity of Fair Value of OTC Derivative Assets and Liabilities (Details) $ in Thousands	Nov. 30, 2019 USD ($)
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	$ 183,095
OTC derivative assets having maturity period of 1 to 5 years	212,848
OTC derivative assets having maturity period of greater than 5 years	149,796
OTC derivative assets cross-maturity netting	(27,115)
Total OTC derivative assets, net of cross-maturity netting	518,624
Cross product counterparty netting	(32,208)
Total OTC derivative assets included in Financial instruments owned	486,416
OTC derivative liabilities having maturity period of 0 to 12 months	124,533
OTC derivative liabilities having maturity period of 1 to 5 years	321,723
OTC derivative liabilities having maturity period of greater than 5 years	189,575
OTC derivative liabilities cross-maturity netting	(27,115)
Total OTC derivative liabilities, net of cross-maturity netting	608,716
Cross product counterparty netting	(32,208)
Total OTC derivative liabilities included in Financial instruments sold, not yet purchased	576,508
Exchange traded derivative assets	37,200
Cash collateral received	126,100
Exchange traded derivative liabilities, with fair value	275,700
Cash collateral pledged	325,000
Equity forwards, swaps and options
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	44,065
OTC derivative assets having maturity period of 1 to 5 years	2,302
OTC derivative assets having maturity period of greater than 5 years	7,442
OTC derivative assets cross-maturity netting	(6,612)
Total OTC derivative assets, net of cross-maturity netting	47,197
OTC derivative liabilities having maturity period of 0 to 12 months	25,342
OTC derivative liabilities having maturity period of 1 to 5 years	173,359
OTC derivative liabilities having maturity period of greater than 5 years	77,052
OTC derivative liabilities cross-maturity netting	(6,612)
Total OTC derivative liabilities, net of cross-maturity netting	269,141
Credit default swaps
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	49
OTC derivative assets having maturity period of 1 to 5 years	1,059
OTC derivative assets having maturity period of greater than 5 years	15
OTC derivative assets cross-maturity netting	(62)
Total OTC derivative assets, net of cross-maturity netting	1,061
OTC derivative liabilities having maturity period of 0 to 12 months	1,245
OTC derivative liabilities having maturity period of 1 to 5 years	3,688
OTC derivative liabilities having maturity period of greater than 5 years	8,160
OTC derivative liabilities cross-maturity netting	(62)
Total OTC derivative liabilities, net of cross-maturity netting	13,031
Total return swaps
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	58,845
OTC derivative assets having maturity period of 1 to 5 years	34,546
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(554)
Total OTC derivative assets, net of cross-maturity netting	92,837
OTC derivative liabilities having maturity period of 0 to 12 months	28,096
OTC derivative liabilities having maturity period of 1 to 5 years	41,160
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(554)
Total OTC derivative liabilities, net of cross-maturity netting	68,702
Foreign currency forwards, swaps and options
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	46,003
OTC derivative assets having maturity period of 1 to 5 years	11,123
OTC derivative assets having maturity period of greater than 5 years	62
OTC derivative assets cross-maturity netting	(4,855)
Total OTC derivative assets, net of cross-maturity netting	52,333
OTC derivative liabilities having maturity period of 0 to 12 months	48,388
OTC derivative liabilities having maturity period of 1 to 5 years	9,786
OTC derivative liabilities having maturity period of greater than 5 years	45
OTC derivative liabilities cross-maturity netting	(4,855)
Total OTC derivative liabilities, net of cross-maturity netting	53,364
Fixed income forwards
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	986
OTC derivative assets having maturity period of 1 to 5 years	0
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	986
OTC derivative liabilities having maturity period of 0 to 12 months	581
OTC derivative liabilities having maturity period of 1 to 5 years	0
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	581
Interest rate swaps, options and forwards
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	33,147
OTC derivative assets having maturity period of 1 to 5 years	163,818
OTC derivative assets having maturity period of greater than 5 years	142,277
OTC derivative assets cross-maturity netting	(15,032)
Total OTC derivative assets, net of cross-maturity netting	324,210
OTC derivative liabilities having maturity period of 0 to 12 months	20,881
OTC derivative liabilities having maturity period of 1 to 5 years	93,730
OTC derivative liabilities having maturity period of greater than 5 years	104,318
OTC derivative liabilities cross-maturity netting	(15,032)
Total OTC derivative liabilities, net of cross-maturity netting	$ 203,897