Fair Value Disclosures - Level 3 Rollforwards (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2023	Nov. 30, 2022	Nov. 30, 2021
Assets:
Total gains/(losses) (realized and unrealized)	$ 38,500	$ 31,800	$ 140,000
Liabilities:
Total gains/(losses) (realized and unrealized)	(62,900)	(465,700)	(12,900)
Transfers of liabilities from Level 2 to Level 3	$ 60,800	$ 172,100	$ 74,300
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenues	Revenues	Revenues
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenues	Revenues	Revenues
Corporate equity securities
Assets:
Beginning balance	$ 240,347	$ 118,489	$ 116,089
Total gains/(losses) (realized and unrealized)	(65,037)	(645)	19,213
Purchases	7,865	171,700	8,778
Sales	(1,228)	(62,474)	(34,307)
Settlements	0	(298)	(49)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	(653)	13,575	8,765
Ending balance	181,294	240,347	118,489
Changes in unrealized gains/(losses) included in earnings for instruments still held	(11,007)	7,286	11,589
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Liabilities:
Beginning balance	750	4,635	4,434
Total gains/(losses) (realized and unrealized)	348	(3,611)	(83)
Purchases	(1,477)	(815)	(21)
Sales	1,055	4,858	318
Settlements	0	0	0
Issuances	0	0	0
Net transfers into/ (out of) Level 3	0	(4,317)	(13)
Ending balance	676	750	4,635
Changes in unrealized gains/ (losses) included in earnings for instruments still held	284	2,382	83
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Corporate debt securities
Assets:
Beginning balance	30,232	11,803	23,146
Total gains/(losses) (realized and unrealized)	1,749	946	1,565
Purchases	4,132	18,686	11,161
Sales	(18,325)	(23,964)	(7,978)
Settlements	(200)	(9)	(1,417)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	8,524	22,770	(14,674)
Ending balance	26,112	30,232	11,803
Changes in unrealized gains/(losses) included in earnings for instruments still held	(703)	(2,087)	1,724
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Liabilities:
Beginning balance	500	482	141
Total gains/(losses) (realized and unrealized)	(35)	88	1,205
Purchases	(187)	(70)	(815)
Sales	0	0	0
Settlements	0	0	(49)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	(154)	0	0
Ending balance	124	500	482
Changes in unrealized gains/ (losses) included in earnings for instruments still held	29	(88)	(139)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
CDOs and CLOs
Assets:
Beginning balance	55,824	31,946	17,972
Total gains/(losses) (realized and unrealized)	31,218	7,099	8,092
Purchases	51,632	44,995	32,618
Sales	(3,199)	(22,600)	(27,332)
Settlements	(56,624)	(16,634)	(5,042)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	(13,989)	11,018	5,638
Ending balance	64,862	55,824	31,946
Changes in unrealized gains/(losses) included in earnings for instruments still held	(10,774)	(10,938)	(4,390)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
RMBS
Assets:
Beginning balance	27,617	1,477	21,826
Total gains/(losses) (realized and unrealized)	(5,709)	(13,210)	(243)
Purchases	10	35,774	708
Sales	0	(372)	(1,183)
Settlements	(247)	(240)	(354)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	(800)	4,188	(19,277)
Ending balance	20,871	27,617	1,477
Changes in unrealized gains/(losses) included in earnings for instruments still held	(1,775)	(7,728)	(131)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
CMBS
Assets:
Beginning balance	839	2,333	2,003
Total gains/(losses) (realized and unrealized)	(331)	(733)	(1,694)
Purchases	0	0	2,445
Sales	0	(749)	(393)
Settlements	0	0	(13)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	0	(12)	(15)
Ending balance	508	839	2,333
Changes in unrealized gains/(losses) included in earnings for instruments still held	(327)	(703)	(733)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Liabilities:
Beginning balance	490	210	35
Total gains/(losses) (realized and unrealized)	0	0	0
Purchases	0	0	(35)
Sales	350	280	210
Settlements	0	0	0
Issuances	0	0	0
Net transfers into/ (out of) Level 3	0	0	0
Ending balance	840	490	210
Changes in unrealized gains/ (losses) included in earnings for instruments still held	0	0	0
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Other ABS
Assets:
Beginning balance	94,677	93,524	79,995
Total gains/(losses) (realized and unrealized)	(17,800)	(6,467)	5,335
Purchases	71,261	74,353	65,277
Sales	(37,088)	(20,362)	(21,727)
Settlements	(26,936)	(39,647)	(45,397)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	33,547	(6,724)	10,041
Ending balance	117,661	94,677	93,524
Changes in unrealized gains/(losses) included in earnings for instruments still held	(20,678)	(26,982)	(14,471)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0
Loans and other receivables
Assets:
Beginning balance	168,875	178,417	186,568
Total gains/(losses) (realized and unrealized)	10,995	(1,912)	1,250
Purchases	55,520	45,536	50,167
Sales	(42,999)	(33,692)	(55,848)
Settlements	(46,383)	(48,218)	(20,442)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	(15,907)	28,744	16,722
Ending balance	130,101	168,875	178,417
Changes in unrealized gains/(losses) included in earnings for instruments still held	4,168	(11,610)	(4,905)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Investments at fair value
Assets:
Beginning balance	161,992	154,373	213,946
Total gains/(losses) (realized and unrealized)	83,382	46,735	112,012
Purchases	8,852	74,984	22,957
Sales	(15,080)	(74,742)	(47,243)
Settlements	(107,963)	(15,951)	(9,809)
Issuances	0	0	0
Net transfers into/ (out of) Level 3	(348)	(23,407)	(137,490)
Ending balance	130,835	161,992	154,373
Changes in unrealized gains/(losses) included in earnings for instruments still held	(5,762)	33,294	25,723
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Loans
Liabilities:
Beginning balance	3,164	9,925	6,913
Total gains/(losses) (realized and unrealized)	(114)	1,197	3,384
Purchases	(1,655)	(5,173)	(469)
Sales	126	0	220
Settlements	0	96	0
Issuances	0	0	0
Net transfers into/ (out of) Level 3	0	(2,881)	(123)
Ending balance	1,521	3,164	9,925
Changes in unrealized gains/ (losses) included in earnings for instruments still held	(992)	(2,484)	(1,523)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Net derivatives
Liabilities:
Beginning balance	59,524	67,769	26,017
Total gains/(losses) (realized and unrealized)	(10,405)	(181,750)	7,246
Purchases	(527)	(1,559)	0
Sales	170	1,285	0
Settlements	(3,496)	0	(1,491)
Issuances	2,158	28,436	44,453
Net transfers into/ (out of) Level 3	3,531	145,343	(8,456)
Ending balance	50,955	59,524	67,769
Changes in unrealized gains/ (losses) included in earnings for instruments still held	6,760	168,304	(7,371)
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	0	0	0
Transfers of liabilities from Level 2 to Level 3	35,600	152,800	16,200
Other secured financings
Liabilities:
Beginning balance	1,712	25,905	1,543
Total gains/(losses) (realized and unrealized)	2,186	(650)	(649)
Purchases	0	0	0
Sales	0	0	0
Settlements	0	(23,543)	0
Issuances	0	0	25,011
Net transfers into/ (out of) Level 3	0	0	0
Ending balance	3,898	1,712	25,905
Changes in unrealized gains/ (losses) included in earnings for instruments still held	(2,186)	650	649
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held		0
Long-term debt
Liabilities:
Beginning balance	661,123	881,732	676,028
Total gains/(losses) (realized and unrealized)	70,945	(280,967)	(22,132)
Purchases	0	0	0
Sales	0	0	0
Settlements	0	(3,919)	0
Issuances	17,140	83,874	169,975
Net transfers into/ (out of) Level 3	(4,611)	(19,597)	57,861
Ending balance	744,597	661,123	881,732
Changes in unrealized gains/ (losses) included in earnings for instruments still held	(28,327)	239,400	85,260
Changes in unrealized gains/ (losses) included in other comprehensive income for instruments still held	(59,706)	41,567	(63,126)
Structured notes
Liabilities:
Transfers of liabilities from Level 2 to Level 3	$ 25,200	$ 19,300	$ 57,900