Discontinued Operation (Details) $ in Thousands		3 Months Ended	6 Months Ended
	Jan. 08, 2014 USD ($) item	May. 31, 2014 USD ($)	May. 31, 2015 USD ($)	May. 31, 2014 USD ($)
Discontinued operation
Net annual rent receivable for each of the first five years	$ 500
Income statement disclosure
Sales revenue			$ 80
Pre tax income (loss)			$ 244
Pretax loss from the sale of assets
Proceeds from sale of real estate assets				$ 169
Imperial's landscape nursery business
Discontinued operation
Present value		$ 4,036		4,036
Income statement disclosure
Sales revenue		69
Pre tax income (loss)		644
Pretax loss from the sale of assets
Consideration received				4,768
Carrying value of assets sold, principally inventory				(4,561)
Curtailment of employee benefit plan				309
Severance and other expenses				(563)
Pretax loss				(47)
Proceeds from sale of real estate assets				732
Note receivable		$ 4,036		$ 4,036
Imperial's landscape nursery business | Inventory and certain assets
Discontinued operation
Non-interest bearing note receivable	$ 4,250
Number of installments in which promissory note will become due | item	2
Amount of promissory note receivable due on June 1, 2014	$ 2,750
Amount of promissory note receivable due on June 1, 2015	$ 1,500
Period of non-competition restrictions	4 years
Proceeds from sale of nursery inventory	$ 732
Discount rate (as a percent)	7.00%
Present value	$ 4,036
Pretax loss from the sale of assets
Note receivable	$ 4,036
Imperial's landscape nursery business | Connecticut production nursery
Discontinued operation
Lease period	10 years
Optional extension period of lease	15 years
Period during which purchase option is available	13 years
Price of land, land improvements and other operating assets under option to purchase	$ 10,500
Price of a portion of land under option to purchase	$ 7,000