Supplemental Financial Statement Information - Cash flow, etc. (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 28, 2019	Feb. 28, 2018
Supplemental Cash Flow Information
Treasury shares		5,000
Treasury stock		$ 186
Exercise of an option to acquire shares of common stock		5,471
Increase (decrease) in accounts payable and accrued liabilities related to additions to real estate assets	$ 998	$ 47
Interest paid
Interest payments	1,619	1,433
Income Taxes
Income Tax Expense (Benefit)	(180)	790
Pretax loss	$ 766	$ 933
Effective income tax rate (as a percent)	23.50%	22.60%
Impact of lower statutory rate applied to deferred tax assets and deferred tax liabilities resulted for the re-measurement of deferred tax assets and liabilities		$ 1,001
Offsetting the net charge for the re-measurement of Griffin’s deferred tax assets and liabilities is an income tax benefit		$ 211
2009 Stock Option Plan
Supplemental Cash Flow Information
Treasury shares		5,000
Treasury stock		$ 186
Exercise of an option to acquire shares of common stock		5,471