Collateralized Transactions - Additional Information (Detail) - USD ($) $ in Thousands	Aug. 31, 2017	Nov. 30, 2016
Banking and Thrift [Abstract]
Fair value of securities received as collateral	$ 27,200,000	$ 25,500,000
Cash and securities segregated and on deposit for regulatory purposes or deposited with clearing and depository organizations	$ 903,744	$ 857,337

Amount of cash subject to withdrawal restrictions, restricted deposits held as compensating balances, and cash and securities segregated in compliance with regulations (such as cash deposited in a special reserve account for the exclusive benefit of customers).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 305
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6478312&loc=d3e61473-112792

Name:	us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant