Related Party Transactions - Schedule of Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2024	Aug. 31, 2023	Aug. 31, 2024	Aug. 31, 2023	Nov. 30, 2023
Assets
Cash and cash equivalents	$ 10,573,471		$ 10,573,471		$ 8,526,363
Financial instruments owned, at fair value	24,038,659		24,038,659		21,747,473
Securities borrowed	7,056,550		7,056,550		7,192,091
Securities purchased under agreements to resell	6,993,024		6,993,024		5,950,549
Receivables:
Brokers, dealers and clearing organizations	2,583,719		2,583,719		2,380,732
Customers	2,060,450		2,060,450		1,705,425
Fees, interest and other	661,038		661,038		630,142
Other assets	3,263,629		3,263,629		2,650,640
Total assets	63,275,098		63,275,098		57,905,161
Liabilities
Financial instruments sold, not yet purchased, at fair value	12,307,086		12,307,086		11,251,154
Securities sold under agreements to repurchase	9,603,530		9,603,530		10,920,606
Payables:
Brokers, dealers and clearing organizations	4,421,053		4,421,053		3,737,810
Customers	3,898,469		3,898,469		3,960,557
Long-term debt	12,922,012		12,922,012		9,698,752
Total liabilities	53,159,331		53,159,331		$ 48,102,620
Revenues
Revenues	2,595,589	$ 2,040,915	7,663,827	$ 5,472,661
Interest expense	912,037	858,806	2,585,627	1,969,450
Net revenues	1,683,552	1,182,109	5,078,200	3,503,211
Non-interest expenses
Business development	68,152	41,467	194,433	121,892
Total non-interest expenses	1,430,865	1,091,038	4,377,517	3,236,203
Investment banking
Revenues
Revenues	927,094	600,190	2,344,743	1,595,463
Principal transactions
Revenues
Revenues	324,501	353,373	1,381,432	1,171,578
Commissions and other fees
Revenues
Revenues	270,643	223,712	787,968	672,294
Interest
Revenues
Revenues	936,786	$ 898,040	2,636,002	$ 2,062,104
Sumitomo Mitsui Banking Corporation Agreement | Related Party
Assets
Cash and cash equivalents	521,701		521,701
Financial instruments owned, at fair value	9,607		9,607
Securities borrowed	15,357		15,357
Securities purchased under agreements to resell	431,802		431,802
Receivables:
Brokers, dealers and clearing organizations	121,618		121,618
Customers	4,163		4,163
Fees, interest and other	3,022		3,022
Other assets	269		269
Total assets	1,107,539		1,107,539
Liabilities
Financial instruments sold, not yet purchased, at fair value	14,983		14,983
Securities sold under agreements to repurchase	538,239		538,239
Payables:
Brokers, dealers and clearing organizations	130,852		130,852
Customers	4,891		4,891
Fees, interest and other	326		326
Long-term debt	0		0
Total liabilities	689,291		689,291
Revenues
Revenues			(33,550)
Interest expense			2,411
Net revenues			(35,961)
Non-interest expenses
Business development			4,570
Total non-interest expenses			4,570
Sumitomo Mitsui Banking Corporation Agreement | Related Party | Investment banking
Revenues
Revenues			455
Sumitomo Mitsui Banking Corporation Agreement | Related Party | Principal transactions
Revenues
Revenues			(38,301)
Sumitomo Mitsui Banking Corporation Agreement | Related Party | Commissions and other fees
Revenues
Revenues			180
Sumitomo Mitsui Banking Corporation Agreement | Related Party | Interest
Revenues
Revenues			4,116
Sumitomo Mitsui Banking Corporation Agreement | Related Party | Revolving Credit Facility | Line of credit
Payables:
Paydown on a credit facility	$ 750,000		$ 750,000