Stockholders' Equity (Details 4) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2015 USD ($) individual	Aug. 31, 2014 USD ($)	Aug. 31, 2015 USD ($) individual $ / shares shares	Aug. 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 (benefit)	$ 30	$ 63	$ 192	$ 146
Related tax benefit (expense)	8	19	$ 49	$ 44
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 (benefit)	30	63	$ 192	$ 276
Related tax benefit (expense)	$ 8	$ 19	$ 49	59
Discontinued operations. | 2009 Stock Option Plan | Employee and directors' stock options
Compensation expense for stock options
Compensation expense (benefit)				130
Related tax benefit (expense)				$ 15