Supplementary Balance Sheet Detail

The following tables present supplementary balance sheet details:



	At December 31,
	2012			2013
	(Dollars in thousands)

Inventories:
Raw materials and supplies	$	230,057		$	184,420
Work in process	213,948			245,160
Finished goods	73,293			78,446
	517,298			508,026
Reserves	(4,233		)	(17,612		)
	$	513,065		$	490,414
Property, plant and equipment:
Land and improvements	$	36,744		$	37,416
Buildings	182,838			196,802
Machinery and equipment and other	1,172,045			1,278,655
Construction in progress	140,732			76,007
	$	1,532,359		$	1,588,880
Other accrued liabilities:
Payrolls (including incentive programs)	$	7,461		$	9,330
Customer prepayments	7,594			9,599
Employee compensation and benefits	10,335			10,136
Other	25,563			11,874
	$	50,953		$	40,939
Other long term obligations:
Postretirement benefits	$	30,465		$	24,852
Pension and related benefits	73,202			54,173
Other	21,338			18,922
	$	125,005		$	97,947

The following table presents an analysis of the allowance for doubtful accounts:



	At December 31,
	2011			2012			2013
	(Dollars in thousands)
Balance at beginning of year	$	3,892		$	4,153		$	7,573
Additions	1,438			5,161			2,914
Deductions	(1,177		)	(1,741		)	(3,769		)
Balance at end of year	$	4,153		$	7,573		$	6,718

Inventories

We allocate fixed production overheads to the costs of conversion based on normal capacity of the production facilities. It also requires that we recognize abnormal amounts of idle facility expense, freight, handling costs, and wasted materials (spoilage) as current period charges. During 2012, costs in excess of normal absorption were $3.5 million. During 2013, there were no costs in excess of normal absorption.

The following table presents an analysis of our inventory reserves:



	At December 31,
	2011			2012			2013
	(Dollars in thousands)
Balance at beginning of year	$	2,716		$	4,709		$	4,233
Additions	4,154			4,052			19,878
Deductions	(2,161		)	(4,528		)	(6,499		)
Balance at end of year	$	4,709		$	4,233		$	17,612

Additions to the reserve included $9.1 million related to the rationalizations discussed in Note 2. The remaining increase in inventory reserves resulted from decreased pricing for certain products in certain markets.