Summary of significant accounting policies (Narrative) (Details) - USD ($) |
6 Months Ended | |
|---|---|---|
May 31, 2020 |
Dec. 01, 2019 |
|
| Likelihood Of Tax Benefit Being Realized Upon Settlement | 50.00% | |
| Lease, Practical Expedients, Package [true false] | true | |
| Lease, Practical Expedient, Use of Hindsight [true false] | true | |
| Lease, Practical Expedient, Land Easement [true false] | true | |
| Operating Lease, Right-of-Use Asset | $ 529,000 | $ 681,000 |
| Operating Lease, Liability | $ 93,006 | |
| ASU 2016-02 [Member] | ||
| Operating Lease, Right-of-Use Asset | 681,000 | |
| ASU 2016-02 [Member] | Restatement Adjustment [Member] | ||
| Operating Lease, Right-of-Use Asset | 786,000 | |
| Operating Lease, Liability | $ 786,000 |