Discontinued Operations (Details) $ in Thousands			12 Months Ended
	Jan. 18, 2014 USD ($)	Jan. 08, 2014 USD ($)	Nov. 30, 2015 USD ($)	Nov. 30, 2014 USD ($) item	Nov. 30, 2013 USD ($)	Jun. 01, 2015 USD ($)	Jun. 01, 2014 USD ($)
Discontinued operation
Proceeds from sale of real estate assets				$ 169
Property and equipment accumulated depreciation			$ 996	988
Imperial's landscape nursery business | Inventory and certain assets
Pretax loss from the sale of assets
Present value				4,036
Held for sale | Imperial's landscape nursery business
Income statement disclosure
Net charge included in cost of sales					$ 10,400
Increase in inventory reserves					500
Held for sale | Imperial's landscape nursery business | Inventory and certain assets
Income statement disclosure
Sales revenue					13,220
Pre tax income (loss)					$ (12,142)
Discontinued operations
Discontinued operation
Proceeds from sale of real estate assets		$ 732
Discontinued operations | Imperial's landscape nursery business
Discontinued operation
Period of non-competition restrictions	4 years
Net annual rent receivable for each of the first five years			$ 500
Discount rate (as a percent)	7.00%
Income statement disclosure
Reclassification of actuarial gains related to entity's postretirement benefits program				451
Pretax loss from the sale of assets
Consideration received				4,768
Carrying value of assets sold, principally inventory				(4,561)
Curtailment of employee benefit program				309
Severance and other expenses				(563)
Pretax loss				$ (47)
Present value	$ 4,036
Discontinued operations | 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
Proceeds from sale of nursery inventory		$ 732
Income statement disclosure
Sales revenue				$ 159
Pre tax income (loss)				$ 259
Discontinued operations | 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