Related Party Transactions - Revenue by Service (Details) - Leucadia [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2015	Aug. 31, 2014
Related Party Transaction [Line Items]
Revenue from related parties	$ 11,000	$ 9,000	$ 22,200	$ 26,200
Investment banking and advisory [Member]
Related Party Transaction [Line Items]
Revenue from related parties	0	2,800	21,200	2,800
Asset management [Member]
Related Party Transaction [Line Items]
Revenue from related parties	102	0	405	0
Commissions and other fees [Member]
Related Party Transaction [Line Items]
Revenue from related parties	$ 1	$ 0	$ 38	$ 0