Segment information (Schedule of Segment and Related Information) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Apr. 30, 2022	Jan. 31, 2022	Apr. 30, 2021	Jan. 31, 2021	Apr. 30, 2022	Apr. 30, 2021
Reportable Segments
Real estate rental revenue	$ 6,615		$ 12,804		$ 17,264	$ 25,558
Real estate operating expenses	4,863		9,718		13,336	18,564
Operating income	1,752		3,086		3,928	6,994
Reconciliation to condensed consolidated net income (loss) attributable to common equity:
Segment NOI	3,386		6,901		8,719	14,570
Deferred rents - straight lining	(51)		(7)		(61)	(213)
Investment income	38		29		64	59
General and administrative expenses	(869)		(1,470)		(2,196)	(2,730)
Loss on investment in tenancy-in-common	(32)		(118)		(156)	(145)
Depreciation	(714)		(2,338)		(2,534)	(4,633)
Net gain (loss) on sale of Maryland properties	(1,232)				68,771
Financing costs	(1,527)		(3,060)		(4,455)	(6,192)
Net income (loss)	(1,001)	$ 69,153	(63)	$ 779	68,152	716
Net (income) loss attributable to noncontrolling interests in subsidiaries	649		72		(22,727)	(149)
Net income (loss) attributable to common equity	(352)		9		45,425	567
Residential [Member]
Reportable Segments
Recurring capital improvements	(158)		(98)		(206)	(180)
Operating Segments [Member]
Reportable Segments
Real estate rental revenue	6,666		12,811		17,325	25,771
Real estate operating expenses	3,280		5,910		8,606	11,201
Operating income	3,386		6,901		8,719	14,570
Operating Segments [Member] | Commercial [Member]
Reportable Segments
Real estate rental revenue	1,945		6,063		6,266	12,414
Real estate operating expenses	1,234		3,184		3,919	5,811
Operating income	711		2,879		2,347	6,603
Operating Segments [Member] | Residential [Member]
Reportable Segments
Real estate rental revenue	4,721		6,748		11,059	13,357
Real estate operating expenses	2,046		2,726		4,687	5,390
Operating income	$ 2,675		$ 4,022		$ 6,372	$ 7,967