Fair Value Disclosures - Quantitative Information about Significant Unobservable Inputs Used in Level 3 Fair Value Measurements (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Aug. 31, 2015	Nov. 30, 2014	May. 31, 2015	Aug. 31, 2014	May. 31, 2014	Nov. 30, 2013
Embedded conversion option [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Sold, Not Yet Purchased	$ 114	$ 693	$ 725	$ 1,432	$ 3,895	$ 9,574
Corporate equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	38,502	20,964	20,547	7,777	16,402	9,884
Corporate debt securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	24,331	22,766	31,917	36,884	31,648	25,666
Collateralized debt obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	81,050	124,650	89,007	43,740	42,313	37,216
Residential mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	86,422	82,557	88,695	81,034	71,962	105,492
Commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	15,147	26,655	17,862	19,327	24,246	17,568
Other asset-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	32,596	2,294	11,857	2,079	45,444	12,611
Loans and other receivables [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	95,399	97,258	108,756	188,025	138,643	145,890
Investments at fair value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	66,209	53,224	$ 131,343	$ 79,001	$ 79,316	$ 66,931
Financial Instruments Owned [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	20,308	54,190
Financial Instruments Owned [Member] | Corporate equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	17,340	19,814
Financial Instruments Owned [Member] | Corporate debt securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	24,331	22,766
Financial Instruments Owned [Member] | Collateralized debt obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	33,075	41,784
Financial Instruments Owned [Member] | Residential mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	86,422	82,557
Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	15,147	26,655
Financial Instruments Owned [Member] | Other asset-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	32,596	2,294
Financial Instruments Owned [Member] | Loans and other receivables [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	85,445	88,154
Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Owned	38,497	8,500
Financial Instruments Sold, Not Yet Purchased [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Sold, Not Yet Purchased	41,508	49,552
Financial Instruments Sold, Not Yet Purchased [Member] | Embedded conversion option [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Sold, Not Yet Purchased	114	693
Financial Instruments Sold, Not Yet Purchased [Member] | Loans and other receivables [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Sold, Not Yet Purchased	$ 10,371	14,450
Financial Instruments Sold, Not Yet Purchased [Member] | Other secured financings at fair value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Market Value of Financial Instruments Sold, Not Yet Purchased		$ 30,825
Level 3 [Member] | Financial Instruments Owned [Member] | Foreign exchange options [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility	11.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Foreign exchange options [Member] | Minimum [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility		13.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Foreign exchange options [Member] | Maximum [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility		23.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Foreign exchange options [Member] | Weighted Average [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility	0.00%	17.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Unfunded commitment [Member] | Minimum [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	12.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Unfunded commitment [Member] | Minimum [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 91
Level 3 [Member] | Financial Instruments Owned [Member] | Unfunded commitment [Member] | Maximum [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	15.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Unfunded commitment [Member] | Maximum [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100
Level 3 [Member] | Financial Instruments Owned [Member] | Unfunded commitment [Member] | Weighted Average [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	13.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Unfunded commitment [Member] | Weighted Average [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100
Level 3 [Member] | Financial Instruments Owned [Member] | Foreign exchange forwards [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant default rate/Credit spread	5.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Forward contracts [Member] | Discounted cash flows [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield		17.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loan commitments [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price		$ 100
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Scenario analysis [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage		24.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Minimum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Underlying stock price	$ 5
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Maximum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Underlying stock price	7
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Weighted Average [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Underlying stock price	$ 6
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Minimum [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	4.6	3.4
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Maximum [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	8.5	4.7
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate equity securities [Member] | Non-exchange traded securities [Member] | Weighted Average [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	6.6	3.6
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	19.00%
Significant Unobservable Input(s), Transaction level	$ 138
Level 3 [Member] | Financial Instruments Owned [Member] | Corporate debt securities [Member] | Convertible bond model [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Discount rate/yield	74.00%	32.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Collateralized debt obligations [Member] | Minimum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	0.00%	0.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	0.00%	0.00%
Significant Unobservable Input(s), Loss severity	25.00%	0.00%
Significant Unobservable Input(s), Yield	10.00%	2.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Collateralized debt obligations [Member] | Maximum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	20.00%	20.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	2.00%	2.00%
Significant Unobservable Input(s), Loss severity	100.00%	70.00%
Significant Unobservable Input(s), Yield	13.00%	51.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Collateralized debt obligations [Member] | Weighted Average [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	17.00%	13.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	2.00%	2.00%
Significant Unobservable Input(s), Loss severity	40.00%	39.00%
Significant Unobservable Input(s), Yield	11.00%	16.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Residential mortgage-backed securities [Member] | Minimum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	0.00%	1.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	1.00%	1.00%
Significant Unobservable Input(s), Loss severity	25.00%	20.00%
Significant Unobservable Input(s), Yield	1.00%	3.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Residential mortgage-backed securities [Member] | Maximum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	50.00%	50.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	8.00%	100.00%
Significant Unobservable Input(s), Loss severity	80.00%	80.00%
Significant Unobservable Input(s), Yield	11.00%	13.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Residential mortgage-backed securities [Member] | Weighted Average [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	12.00%	13.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	5.00%	14.00%
Significant Unobservable Input(s), Loss severity	52.00%	50.00%
Significant Unobservable Input(s), Yield	5.00%	7.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Scenario analysis [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage		90.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Minimum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	8.00%	8.00%
Significant Unobservable Input(s), Cumulative loss rate	2.00%	4.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Maximum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	20.00%	12.00%
Significant Unobservable Input(s), Cumulative loss rate	54.00%	72.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Commercial mortgage-backed securities [Member] | Weighted Average [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	14.00%	11.00%
Significant Unobservable Input(s), Cumulative loss rate	15.00%	15.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate		8.00%
Significant Unobservable Input(s), Constant default rate/Credit spread		3.00%
Significant Unobservable Input(s), Loss severity		70.00%
Significant Unobservable Input(s), Yield		7.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Minimum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	0.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	0.00%
Significant Unobservable Input(s), Loss severity	0.00%
Significant Unobservable Input(s), Yield	1.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Minimum [Member] | Over collateralization percentage [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Over collateralization percentage	111.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Maximum [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	24.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	9.00%
Significant Unobservable Input(s), Loss severity	100.00%
Significant Unobservable Input(s), Yield	25.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Maximum [Member] | Over collateralization percentage [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Over collateralization percentage	125.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Weighted Average [Member] | Discounted cash flows [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	10.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	5.00%
Significant Unobservable Input(s), Loss severity	77.00%
Significant Unobservable Input(s), Yield	10.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Other asset-backed securities [Member] | Weighted Average [Member] | Over collateralization percentage [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Over collateralization percentage	123.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple	6.9
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Minimum [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple		3.4
Significant Unobservable Input(s), Discount rate/yield	2.00%
Significant Unobservable Input(s), Yield		3.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Minimum [Member] | Scenario analysis [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage	34.00%	10.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Minimum [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 91	$ 100
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Maximum [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple		8.2
Significant Unobservable Input(s), Discount rate/yield	13.00%
Significant Unobservable Input(s), Yield		5.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Maximum [Member] | Scenario analysis [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage	77.00%	41.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Maximum [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100	$ 101
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Weighted Average [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), EBITDA multiple		7.6
Significant Unobservable Input(s), Yield	10.00%	4.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Weighted Average [Member] | Scenario analysis [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Estimated recovery percentage	39.00%	36.00%
Level 3 [Member] | Financial Instruments Owned [Member] | Loans and other receivables [Member] | Weighted Average [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 97.0	$ 100.3
Level 3 [Member] | Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Transaction level		$ 50
Level 3 [Member] | Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member] | Minimum [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Transaction level	3
Level 3 [Member] | Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member] | Maximum [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Transaction level	56
Level 3 [Member] | Financial Instruments Owned [Member] | Investments at fair value [Member] | Private equity securities [Member] | Weighted Average [Member] | Market approach [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Transaction level	$ 10
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Minimum [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility		13.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Maximum [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility		23.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Foreign exchange options [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility	11.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Foreign exchange options [Member] | Weighted Average [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility		17.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Equity options [Member] | Option model [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Volatility	42.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Equity options [Member] | Default rate [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Default probability	0.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield		5.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Discounted cash flows [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant prepayment rate	20.00%
Significant Unobservable Input(s), Constant default rate/Credit spread	2.00%
Significant Unobservable Input(s), Loss severity	30.00%
Significant Unobservable Input(s), Yield	11.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Constant default rate/Credit spread		0.45%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Minimum [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	4.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Minimum [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 91	$ 89
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Maximum [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	15.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Maximum [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100	100
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Weighted Average [Member] | Market approach [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Yield	13.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Unfunded commitment [Member] | Weighted Average [Member] | Comparable pricing [Member] | Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 95.8	$ 92.0
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Embedded conversion option [Member] | Option valuation model [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Historical volatility	22.00%	19.00%
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Commercial Loan [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price	$ 100	$ 100
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Other secured financings at fair value [Member] | Minimum [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price		81
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Other secured financings at fair value [Member] | Maximum [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price		100
Level 3 [Member] | Financial Instruments Sold, Not Yet Purchased [Member] | Other secured financings at fair value [Member] | Weighted Average [Member] | Comparable pricing [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Significant Unobservable Input(s), Comparable bond or loan price		$ 98.7