Stockholders' Equity (Details 4) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	May. 31, 2015 USD ($) individual	May. 31, 2014 USD ($)	May. 31, 2015 USD ($) individual $ / shares shares	May. 31, 2014 USD ($) $ / shares shares
Employee and directors' stock options
Other Disclosures
Number of option holders | individual	15		15
2009 Stock Option Plan
Griffin Stock Option Plan
Granted (in shares) | shares			8,282	8,532
2009 Stock Option Plan | Employee and directors' stock options
Griffin Stock Option Plan
Expiration term			10 years
Assumptions used in determining the fair value of the stock options granted
Expected volatility (as a percent)			40.80%	38.90%
Range of risk free interest rate (as a percent)			2.00%	2.20%
Expected option term			8 years 6 months	8 years 6 months
Annual dividend yield (as a percent)			0.70%	0.70%
Compensation expense for stock options
Compensation expense	$ 69	$ 60	$ 162	$ 83
Related tax benefit	23	16	$ 41	$ 40
2009 Stock Option Plan | Employee and directors' stock options | Non-employee directors
Griffin Stock Option Plan
Fair values of stock options granted (in dollars per share) | $ / shares			$ 14.39	$ 12.42
Granted (in shares) | shares			8,282	8,532
Continuing operations | 2009 Stock Option Plan | Employee and directors' stock options
Compensation expense for stock options
Compensation expense	69	60	$ 162	$ 213
Related tax benefit	$ 23	$ 16	$ 41	40
Discontinued operations | 2009 Stock Option Plan | Employee and directors' stock options
Compensation expense for stock options
Compensation expense				$ (130)