Income Taxes (Components of Deferred Income Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred income tax assets:
Pension	$ 16,526	$ 35,813
Non-pension postretirement benefits	27,198	26,085
Other accrued liabilities	20,213	21,045
Receivables	1,445	1,279
Net operating loss and charitable contribution carry forwards	45,592	23,746
Tax credits	9,770	9,026
Total deferred income tax assets	120,744	116,994
Deferred income tax liabilities:
Property, plant and equipment	23,196	27,321
Inventories	4,377	4,932
Intangibles and other assets	12,392	11,062
Total deferred income tax liabilities	39,965	43,315
Net deferred income tax asset (liability):
Net deferred income tax asset before valuation allowance	80,779	73,679
Valuation allowance	(77,629)	(76,452)
Net deferred income tax asset (liability)	$ 3,150	$ (2,773)