Business Segments - Business segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 8,823	$ 8,302
Operating profit	6,600	2,345
Corporate expenses unallocated to discontinued operations	0	(919)
Interest expense	481	445
Depreciation, depletion and amortization	1,959	1,865
Cash items	1,174		$ 419
Total identifiable net assets	257,109		252,478
Asset Management
Segment Reporting Information [Line Items]
Revenues	6,915	6,757
Operating profit before corporate expenses	3,388	3,386
Allocated corporate expenses	(378)	(300)
Interest expense	481	445
Capital expenditures	9,237	905
Depreciation, depletion and amortization	1,798	1,786
Total identifiable net assets	159,216		151,023
Mining royalty lands
Segment Reporting Information [Line Items]
Revenues	1,659	1,344
Operating profit before corporate expenses	1,525	1,200
Allocated corporate expenses	(55)	(318)
Capital expenditures	0	0
Depreciation, depletion and amortization	34	31
Total identifiable net assets	39,298		39,300
Land Development and Construction
Segment Reporting Information [Line Items]
Revenues	249	201
Operating profit before corporate expenses	2,419	(528)
Allocated corporate expenses	(299)	(176)
Capital expenditures	1,302	833
Depreciation, depletion and amortization	64	66
Total identifiable net assets	56,916		60,682
Corporate
Segment Reporting Information [Line Items]
Total identifiable net assets	505		$ 1,054
Total Segments
Segment Reporting Information [Line Items]
Revenues	8,823	8,302
Operating profit	6,600	2,345
Allocated corporate expenses	(732)	(1,713)
Corporate expenses unallocated to discontinued operations	0	(919)
Interest expense	481	445
Capital expenditures	10,539	1,738
Depreciation, depletion and amortization	$ 1,896	$ 1,883