Stockholders' Equity - Stock Repurchases, Cash Dividend (Details) - USD ($)	12 Months Ended			24 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2017
Stock Repurchases
Stock repurchased	$ 1,474,000	$ 3,354,000
Cash Dividend
Cash dividend paid	$ 1,514,000	1,546,000	$ 1,030,000
Stock Repurchases
Stock Repurchases
Stock repurchase program, authorized amount		$ 5,000,000
Stock repurchased (in shares)	47,173			152,173
Stock repurchased	$ 1,474,000			$ 4,828,000
Common Stock
Cash Dividend
Cash dividends declared (in dollars per share)	$ 0.40	$ 0.30	$ 0.30