Revenues from Contracts with Customers - Components of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 632,995	$ 602,335	$ 1,408,936	$ 1,049,742
Principal transactions	467,283	248,831	839,185	483,129
Revenues from arrangements with strategic partners	2,339	549	9,655	911
Interest	211,941	418,451	506,609	779,426
Other	(47,275)	44,327	(17,546)	56,157
Total revenues	1,267,283	1,314,493	2,746,839	2,369,365
Commissions and other fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	243,267	167,698	422,802	322,840
Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	387,491	430,087	979,493	715,683
Asset management and revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 2,237	$ 4,550	$ 6,641	$ 11,219