Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended		12 Months Ended
	Jan. 18, 2014	Jan. 08, 2014 item	Nov. 30, 2014	Nov. 30, 2013	Dec. 01, 2012	Jan. 18, 2014	Jan. 08, 2014
Discontinued operation
Net annual rent receivable for each of the first five years		$ 500					$ 500
Proceeds from sale of real estate assets		732	169
Property and Equipment, gross			1,218	15,998
Accumulated depreciation			988	14,048
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 plan			309
Severance and other expenses			(563)
Pretax loss			(47)
Present value		4,036					4,036
Assets:
Accounts receivable				1,151
Inventories				4,116
Other			36	360
Assets			36	5,627
Liabilities:
Accounts payable and accrued liabilities			8	768
Manchester, Connecticut warehouse
Discontinued operation
Selling expenses paid out of the proceeds			438
Selling expenses paid separately			25
Proceeds from sale of real estate assets			15,537
Pretax gain included in results for discontinued operations			2,886
Proceeds from property sale deposited in escrow account				15,562
Income statement disclosure
Rental revenue					273
Pre tax income (loss)					221
Imperial's landscape nursery business
Income statement disclosure
Net charge included in cost of sales			10,400
Increase in inventory reserves			500		380
Pretax loss from the sale of assets
Severance and other expenses		563
Imperial's landscape nursery business | Inventory and certain assets
Discontinued operation
Non-interest bearing note receivable		4,250					4,250
Number of installments in which promissory note will become due		2
Amount of promissory note receivable due on June 1, 2014		2,750					2,750
Amount of promissory note receivable due on June 1, 2015		1,500					1,500
Period of non-competition restrictions		4 years
Proceeds from sale of nursery inventory		732
Discount rate (as a percent)	7.00%
Income statement disclosure
Sales revenue			159	13,220	12,376
Pre tax income (loss)			259	(12,142)	(1,260)
Pretax loss from the sale of assets
Present value	4,036					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					10,500
Price of a portion of land under option to purchase		7,000					7,000
Property and Equipment, gross	11,485					11,485
Accumulated depreciation	$ 9,850					$ 9,850