Investment in Limited Partnership - Funds in the Premium/Expense Reserve Account (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019
Investments in and Advances to Affiliates [Line Items]
Premiums and expenses	$ 30,289	$ 8,210	$ 85,241	$ 8,210
Class B Interests
Investments in and Advances to Affiliates [Line Items]
Premiums and expenses	2,000		6,000
First
Investments in and Advances to Affiliates [Line Items]
Premiums and expenses	28,289	8,210	79,241	8,210
Second | Class B Interests
Investments in and Advances to Affiliates [Line Items]
Premiums and expenses	2,000	0	6,000	0
Third | Class B Interests
Investments in and Advances to Affiliates [Line Items]
Premiums and expenses	0	0	0	0
Fourth
Investments in and Advances to Affiliates [Line Items]
Premiums and expenses	$ 0	$ 0	$ 0	$ 0