Fair Value Measurements - Discount Rate Used to Estimate Fair Value of Investment in Partnership (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2020 USD ($)	Aug. 31, 2019 USD ($)	Aug. 31, 2020 USD ($)	Aug. 31, 2019 USD ($)	Nov. 30, 2019 USD ($)	[1]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in limited partnership	$ 152,450		$ 152,450		$ 137,849
Change in Value	$ 4,250	$ (5,821)	$ 20,601	$ (5,821)
Discount rate | 0.50% Decrease
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted Average Rate	0.1354		0.1354
Investment in limited partnership	$ 156,438		$ 156,438
Change in Value			$ 3,988
Discount rate | No Change
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted Average Rate	0.1404		0.1404
Investment in limited partnership	$ 152,450		$ 152,450
Change in Value			$ 0
Discount rate | 0.50% Increase
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted Average Rate	0.1454		0.1454
Investment in limited partnership	$ 148,616		$ 148,616
Change in Value			$ (3,834)

[1] Derived from audited consolidated financial statements.