Long-Term Debt (Details) (USD $)	12 Months Ended		12 Months Ended													12 Months Ended								0 Months Ended				0 Months Ended					0 Months Ended				12 Months Ended		12 Months Ended
	Nov. 30, 2013	Dec. 01, 2012	Nov. 30, 2013 Interest rate swap agreement item	Dec. 01, 2012 Interest rate swap agreement	Dec. 03, 2011 Interest rate swap agreement	Nov. 30, 2013 Nonrecourse mortgages	Dec. 01, 2012 Nonrecourse mortgages	Nov. 30, 2013 Nonrecourse mortgages: 6.30%, due May 1, 2014	Dec. 01, 2012 Nonrecourse mortgages: 6.30%, due May 1, 2014	Nov. 30, 2013 Nonrecourse mortgages: 5.73%, due August 1, 2015	Dec. 01, 2012 Nonrecourse mortgages: 5.73%, due August 1, 2015	Nov. 30, 2013 Nonrecourse mortgages: 8.13%, due April 1, 2016	Dec. 01, 2012 Nonrecourse mortgages: 8.13%, due April 1, 2016	Nov. 30, 2013 Nonrecourse mortgages: 7.0%, due October 1, 2017	Dec. 01, 2012 Nonrecourse mortgages: 7.0%, due October 1, 2017	Nov. 30, 2013 Nonrecourse variable rate mortgage, due October 2, 2017 item	Dec. 01, 2012 Nonrecourse variable rate mortgage, due October 2, 2017	Jun. 16, 2012 Nonrecourse variable rate mortgage, due October 2, 2017 item	Nov. 30, 2013 Nonrecourse variable rate mortgage, due October 2, 2017 Interest rate swap agreement	Nov. 30, 2013 Nonrecourse variable rate mortgage, due February 1, 2019	Dec. 01, 2012 Nonrecourse variable rate mortgage, due February 1, 2019	Nov. 30, 2013 Nonrecourse variable rate mortgage, due August 1, 2019	Dec. 01, 2012 Nonrecourse variable rate mortgage, due August 1, 2019	Apr. 01, 2013 Nonrecourse Variable rate mortgage, due January 27, 2020	Apr. 01, 2013 Nonrecourse Variable rate mortgage, due January 27, 2020	Nov. 30, 2013 Nonrecourse Variable rate mortgage, due January 27, 2020	Dec. 01, 2012 Nonrecourse Variable rate mortgage, due January 27, 2020	Aug. 28, 2013 Nonrecourse Variable rate mortgage, due September 1, 2023	Nov. 30, 2013 Nonrecourse Variable rate mortgage, due September 1, 2023	Aug. 28, 2013 Nonrecourse Variable rate mortgage, due September 1, 2023 Industrial building in Lower Nazareth, Pennsylvania sqft	Apr. 01, 2013 Nonrecourse mortgages: 5.25%, due January 27, 2020	Sep. 30, 2012 Nonrecourse mortgages: 6.08%, due January 1, 2013	Apr. 24, 2013 Webster Credit Line	Nov. 30, 2013 Webster Credit Line	Apr. 24, 2013 Webster Credit Line Griffin Center South, Bloomfield, CT sqft	Apr. 24, 2013 Webster Credit Line Single-story office building in Griffin Center sqft	Nov. 30, 2013 Doral Credit Line	Dec. 01, 2012 Doral Credit Line	Nov. 30, 2013 Capital leases	Dec. 01, 2012 Capital leases	Dec. 03, 2011 Capital leases	Aug. 28, 2013 2023 First Niagara Mortgage Interest rate swap agreement	Aug. 28, 2013 2023 First Niagara Mortgage Interest rate swap agreement Cash flow hedges
Long-Term Debt
Interest rate (as a percent)								6.30%	6.30%	5.73%	5.73%	8.13%	8.13%	7.00%	7.00%																5.25%	6.08%
Total	$ 66,793,000	$ 59,561,000				$ 66,708,000	$ 59,489,000	$ 99,000	$ 289,000	$ 18,615,000	$ 19,018,000	$ 3,603,000	$ 3,943,000	$ 5,779,000	$ 6,016,000	$ 6,563,000	$ 6,726,000			$ 11,150,000	$ 11,396,000	$ 7,869,000	$ 8,034,000			$ 3,961,000	$ 4,067,000		$ 9,069,000										$ 85,000	$ 72,000
Less: current portion	(2,101,000)	(1,869,000)
Total long-term debt	64,692,000	57,692,000
Annual principal payment requirements under the terms of the nonrecourse mortgage loans
2014						2,066,000
2015						19,828,000
2016						4,144,000
2017						11,877,000
2018						936,000
Debt disclosures
Aggregate book value of land and buildings pledged as collateral						71,100,000																												10,600,000
Borrowings by subsidiary																												9,100,000
Area of collateralized properties (in square feet)																														228,000					235,000	48,000
Lease term of existing full building tenant	5 years
Term of debt																												10 years					2 years
Amortization period of debt																25 years												25 years
Variable interest rate base																one month LIBOR								one month LIBOR				one month LIBOR					one month LIBOR				prime rate
Variable interest rate margin (as a percent)																2.75%								2.50%				1.95%					2.75%				1.50%
Notional principal amount of interest rate swap agreement																																											9,100,000
Fixed interest rate for the final nine years of the loan pursuant to interest rate swap agreement (as a percent)																			3.86%					3.91%	3.91%																	4.79%
Maximum borrowing capacity																																	12,500,000
Variable interest rate percentage, option																																					5.875%
Borrowings under credit line																																		0			0	0
Amount paid for the loan modification	70,000																							70,000
Minimum percentage of difference required between the present values of the future payments under the existing loan and the modified loan																								10.00%	10.00%
Deferred costs related to the existing loan with First Niagara Bank																									216,000
Number of subsidiaries																		2
Number of collateralized industrial buildings																2
Ineffectiveness on cash flow hedges	0
Anticipated ineffectiveness on cash flow hedges	0
Number of agreements containing credit risk related contingent features			0
Recognized net gains (losses) (included in other comprehensive loss), before taxes, on interest rate swap agreements			969,000	(776,000)	(934,000)
Loss expected to be reclassified over next twelve months from accumulated other comprehensive loss to interest expense			998,000
Net fair values of interest rate swap agreements included in other noncurrent assets and liabilities	2,222,000
Net fair values of interest rate swap agreements included in other noncurrent assets	63,000
Net fair values of interest rate swap agreements included in other noncurrent liabilities	2,285,000	3,191,000
Future minimum lease payments under capital leases and the present value of such payments
2014																																							39,000
2015																																							33,000
2016																																							17,000
2017																																							3,000
Total minimum lease payments																																							92,000
Less: amounts representing interest																																							(7,000)
Present value of minimum lease payments																																							85,000
Current portion of present value of minimum lease payments																																							35,000
Capital leases
Capital leases, gross	371,000	406,000
Accumulated amortization	(288,000)	(334,000)
Capital leases, net	83,000	72,000
Amortization expense																																							$ 36,000	$ 39,000	$ 39,000