Stockholders' Equity - Per Share Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2017
Earnings per share:
Net income (loss)	$ 3,668	$ (1,653)	$ 4,627
Weighted average shares outstanding for computation of basic per share results	5,070,000	5,023,000	5,010,000
Incremental shares from assumed exercise of Griffin stock options	36,000		28,000
Adjusted weighted average shares for computation of diluted per share results	5,106,000	5,023,000	5,038,000
Incremental shares from assumed exercise of stock options excluded due to anti-dilutive effect		57,000