Supplementary Balance Sheet Detail (Tables)

3 Months Ended

Mar. 31, 2013

Balance Sheet Related Disclosures [Abstract]

Schedule Of Amounts Recognized In Balance Sheet

	At December 31,
	2011			2012
	(Dollars in thousands)
Accounts and notes receivable, net:
Trade	$	224,905		$	244,000
Allowance for doubtful accounts	(4,153		)	(7,571		)
	$	220,752		$	236,429
Inventories:
Raw materials and supplies	$	168,982		$	230,057
Work in process	205,968			213,948
Finished goods	73,821			73,293
	448,771			517,298
Reserves	(4,709		)	(4,233		)
	$	444,062		$	513,065
Property, plant and equipment:
Land and improvements	$	34,896		$	36,744
Buildings	175,588			182,838
Machinery and equipment and other	1,105,440			1,172,045
Construction in progress	115,508			140,732
	$	1,431,432		$	1,532,359
Other accrued liabilities:
Payrolls (including incentive programs)	$	7,624		7,461
Customer prepayments	8,478			7,594
Employee compensation and benefits	11,680			10,335
Other	12,393			25,563
	$	40,175		$	50,953
Other long term obligations:
Postretirement benefits	$	29,630		$	30,465
Pension and related benefits	75,840			73,202
Other	25,830			21,338
	$	131,300		$	125,005

Schedule Of Analysis Of The Allowance For Doubtful Accounts

	At December 31,
	2010			2011			2012
	(Dollars in thousands)
Balance at beginning of year	$	4,545		$	3,892		$	4,153
Additions	1,004			1,438			5,159
Deductions	(1,657		)	(1,177		)	(1,741		)
Balance at end of year	$	3,892		$	4,153		$	7,571

Schedule Of Inventory Reserves

	At December 31,
	2010			2011			2012
	(Dollars in thousands)
Balance at beginning of year	$	2,518		$	2,716		$	4,709
Additions	2,844			4,154			4,052
Deductions	(2,646		)	(2,161		)	(4,528		)
Balance at end of year	$	2,716		$	4,709		$	4,233