Mortgages, construction loan payable and credit line (Schedule of Debt) (Details) - USD ($) $ in Thousands	Oct. 31, 2016	Oct. 31, 2015
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ 2,521	$ 3,129
Total mortgages, notes payable and credit line	329,719	307,899
Mortgages [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	215,752	215,946
Unamortized debt issuance costs	1,887	1,909
Mortgages [Member] | Frederick, MD [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	22,000	22,000
Unamortized debt issuance costs	23	62
Mortgages [Member] | Rockaway, NJ Mortgage [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	17,141	17,596
Unamortized debt issuance costs	138	167
Mortgages [Member] | Westwood, NJ #2 [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	20,801	21,355
Unamortized debt issuance costs	197	229
Mortgages [Member] | Patchogue, NY [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	5,231	5,243
Unamortized debt issuance costs	25	56
Mortgages [Member] | Wayne, NJ Mortgage 1 [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	18,054	18,378
Unamortized debt issuance costs	70	95
Mortgages [Member] | River Edge, NJ First Mortgage [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	10,659	10,852
Unamortized debt issuance costs	122	139
Mortgages [Member] | Refinanced Maywood, NJ Mortgage [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	8,087	8,234
Unamortized debt issuance costs	99	113
Mortgages [Member] | Westwood, NJ #3 [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	21,098	21,545
Unamortized debt issuance costs	135	169
Mortgages [Member] | Second Wayne, NJ Mortgage [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	25,749	25,038
Unamortized debt issuance costs	332	22
Mortgages [Member] | Hackensack, NJ [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	29,901	30,567
Unamortized debt issuance costs	50	70
Mortgages [Member] | Damascus, MD [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	20,831	18,938
Unamortized debt issuance costs	427	486
Total mortgages, notes payable and credit line	20,000	20,000
Mortgages [Member] | Middletown, NY Mortgage [Member]
Debt Instrument [Line Items]
Fixed rate mortgage loans	16,200	16,200
Unamortized debt issuance costs	269	301
Notes Payable, Other Payables [Member] | Baltimore, MD [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs	634	1,220
Total mortgages, notes payable and credit line	113,967	91,953
Provident Bank [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs
Total mortgages, notes payable and credit line