Goodwill and Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Dec. 01, 2019	Dec. 01, 2018
Goodwill [Roll Forward]
Balance, at beginning of period	$ 1,642,170	$ 1,647,089
Translation adjustments	1,325	(5,319)
Goodwill acquired during the period	104	400
Balance, at end of period	1,643,599	1,642,170
Investment Banking and Capital Markets
Goodwill [Roll Forward]
Balance, at beginning of period	1,638,778
Balance, at end of period	1,640,201	1,638,778
Accumulated goodwill impairments				$ 51,900
Goodwill, gross				1,690,700
Asset Management
Goodwill [Roll Forward]
Balance, at beginning of period	3,392
Balance, at end of period	$ 3,398	$ 3,392
Accumulated goodwill impairments				2,100
Goodwill, gross				$ 5,500
Subsequent event | Investment Banking and Capital Markets
Goodwill [Roll Forward]
Accumulated goodwill impairments			$ 51,900
Goodwill, gross			1,692,100
Subsequent event | Asset Management
Goodwill [Roll Forward]
Accumulated goodwill impairments			2,100
Goodwill, gross			$ 5,500