Stockholders' Equity - Per Share Results (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019
Earnings per share:
Net (loss) income	$ (641)	$ 1,017	$ (1,654)	$ 6,250
Weighted average shares outstanding for computation of basic per share results	5,179,000	5,073,000	5,126,000	5,068,000
Incremental shares from assumed exercise of Griffin stock options		40,000		34,000
Adjusted weighted average shares for computation of diluted per share results	5,179,000	5,113,000	5,126,000	5,102,000
Incremental shares from assumed exercise of stock options excluded due to anti-dilutive effect			76,000	60,000
Warrant
Earnings per share:
Incremental shares from assumed exercise of stock options excluded due to anti-dilutive effect	504,590		504,590