Current Assets and Current Liabilities (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Receivables
Balance at beginning of year	$ 2,777,000	$ 2,423,000	$ 2,938,000
Charged to expense	2,022,000	1,302,000	532,000
Accounts written off	(1,261,000)	(948,000)	(1,047,000)
Balance at end of year	3,538,000	2,777,000	2,423,000
Other Receivables
Allowance for other receivables	9,000,000
Reserve on note receivable and other contractual payments due from a specific buyer of some of the coal cleaning facilities (as a percent)	100.00%
Gain on disposal of discontinued operations resulting from collection of receivable	2,000,000
Inventories
Raw materials	12,017,000	9,909,000
Finished goods	38,616,000	27,474,000
Inventories	50,633,000	37,383,000
Other Accrued Liabilities
Products and services received but not yet invoiced	19,870,000	24,355,000
Litigation	2,795,000	16,012,000
Other	19,092,000	14,901,000
Other Accrued Liabilities, Current	$ 41,757,000	$ 55,268,000