Business Segments - Business segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Segment Reporting Information [Line Items]
Revenues	$ 8,948	$ 8,007	$ 17,250	$ 15,236
Interest expense	620	310	1,065	599
Capital expenditures - Real estate taxes	1,234	879	2,329	1,719
Depreciation, depletion and amortization			3,851	3,384
Cash items	717		717		$ 1,074
Discontinued operations identifiable net assets					59,465
Total identifiable net assets	252,085		252,085		313,071
Asset Management
Segment Reporting Information [Line Items]
Revenues	7,330	6,580	14,087	12,340
Operating profit	3,187	2,840	6,573	5,548
Corporate expenses	(236)	(178)	(426)	(356)
Interest expense	620	310	1,065	599
Depreciation, depletion and amortization	1,776	1,619	3,562	3,151
Identifiable net assets	152,222		152,222		144,420
Mining royalty land
Segment Reporting Information [Line Items]
Revenues	1,335	1,226	2,679	2,494
Operating profit	1,191	1,068	2,391	2,196
Corporate expenses	(250)	(189)	(451)	(378)
Capital expenditures	0	0	0	0
Depreciation, depletion and amortization	30	28	61	56
Identifiable net assets	40,459		40,459		39,368
Land Development and Construction
Segment Reporting Information [Line Items]
Revenues	283	201	484	402
Operating profit	(739)	(363)	(1,267)	(705)
Corporate expenses	(140)	(105)	(251)	(210)
Depreciation, depletion and amortization	72	46	138	92
Identifiable net assets	57,459		57,459		67,136
Combined Land Development and Construction and Asset Management
Segment Reporting Information [Line Items]
Capital expenditures	319	436	1,610	3,570
Capital expenditures - Capitalized interest	248	477	569	993
Capital expenditures - Internal labor	85	100	184	195
Capital expenditures - Real estate taxes	39	16	66	40
Corporate
Segment Reporting Information [Line Items]
Corporate expenses	(692)	(418)	(984)	(553)
Identifiable net assets	1,228		1,228		$ 1,608
Total Segments
Segment Reporting Information [Line Items]
Revenues	8,948	8,007	17,250	15,236
Operating profit	2,159	1,822	4,504	3,998
Unallocated to discontinued operations	(162)	(833)	(1,081)	(1,544)
Interest expense	620	310	1,065	599
Capital expenditures	691	1,029	2,429	4,798
Depreciation, depletion and amortization	$ 1,878	$ 1,693	$ 3,761	$ 3,299