Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Allowance for doubtful accounts on accounts receivable	$ 4,232	$ 3,588	$ 5,824
Accumulated depreciation and amortization on property, plant and equipment	$ 826,781	$ 815,720	$ 793,418
Common stock, par value	$ 2.25	$ 2.25	$ 2.25
Common stock, shares authorized	40,000,000	40,000,000	40,000,000
Common stock, shares issued	0	0	0
Common stock, shares outstanding	26,781,785	26,781,785	26,781,785