Leases - lessee (Details)	3 Months Ended	12 Months Ended
	Feb. 29, 2020 USD ($)	Nov. 30, 2016 ft²	Dec. 01, 2019 USD ($)
Operating leases assets and liabilities
Operating Lease, Right-of-Use Asset	$ 799,000		$ 858,000
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]			us-aap:OtherAssets
Operating Lease, Liability	$ 829,000		$ 858,000
Operating Lease, Liability, Statement of Financial Position [Extensible List]			Other Liabilities.
Lessee, Operating Sublease, Description [Abstract]
Term of sublease		10 years
Area of subleased property | ft²		1,920
Lease terms
Discount rate	3.50%
Lease expense	$ 34.0
Weighted-average remaining lease term	6 years 7 months 6 days