Investments - JCP Fund V - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	May 31, 2019	Nov. 30, 2018
Schedule of Equity Method Investments [Line Items]
Financial instruments owned, at fair value	$ 16,095,884	$ 16,399,526
JCP Fund V
Schedule of Equity Method Investments [Line Items]
Financial instruments owned, at fair value	28,400	31,900
Unfunded portion of equity commitment to subsidiary	$ 9,500	9,700
Percent of financial information presented	100.00%
Ownership percentage	35.10%
Maximum | JCP Fund V
Schedule of Equity Method Investments [Line Items]
Total committed equity capitalization	$ 85,000	$ 85,000