Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Deferred tax assets:
Pension and postretirement benefits	$ 77,076	$ 63,124
Inventories	3,771	2,662
Accrued compensation and benefits	2,027	1,606
Accrued expenses and other	2,085	2,093
Tax attributes	778	1,385
Valuation Allowance	(128)
Total deferred tax assets	95,633	82,070
Deferred tax liabilities:
Property, plant and equipment, net	(34,109)	(29,789)
Intangible and other	(1,271)	(1,345)
Total	(35,380)	(31,134)
Net deferred tax assets (liabilities)	60,253	50,936
Current deferred tax assets	6,295	6,297
Deferred income taxes-long term portion	53,958	44,639
State tax net operating loss	24	5,013
Tax credits	778	606
Foreign net operating loss	483	1,259
Undistributed losses of foreign subsidiaries	55,037
Provision for U.S. income taxes	0
Conversion Services Arrangement
Deferred tax assets:
Total deferred tax assets	$ 10,024	$ 11,200