Business Segments - Business segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues	$ 40,019	$ 38,820
Operating profit	5,098	4,124
Interest expense	472	311
Capital expenditures (a)	4,201	12,500
Depreciation, depletion and amortization	4,248	3,775
Cash items	895	579	1,013	502
Total identifiable net assets	312,410		313,071
Pipeline
Capital expenditures (a)		3,397
Transportation
Revenues	31,717	31,591
Operating profit	2,752	1,948
Corporate expenses	(692)	(492)
Capital expenditures (a)	2,463	8,731
Depreciation, depletion and amortization	2,261	2,030
Identifiable net assets	59,230		59,465
Mining royalty land
Revenues	1,344	1,268
Operating profit	1,200	1,128
Corporate expenses	(281)	(189)
Interest expense	40	26
Capital expenditures (a)	0	0
Depreciation, depletion and amortization	31	28
Identifiable net assets	39,272		39,368
Developed property rentals
Revenues	6,958	5,961
Operating profit	2,858	2,366
Corporate expenses	(421)	(283)
Interest expense	432	285
Capital expenditures (a)	1,291	3,134
Capital expenditures - Capitalized interest	321	516
Capital expenditures - Internal labor	99	95
Capital expenditures - Real estate taxes	27	24
Depreciation, depletion and amortization	1,834	1,599
Identifiable net assets	211,412		211,556
Corporate
Corporate expenses	(318)	(354)
Depreciation, depletion and amortization	122	118
Identifiable net assets	$ 1,601		$ 1,669