Supplementary balance sheet detail

12 Months Ended

Dec. 31, 2017

(10) Supplementary balance sheet detail

The following tables present supplementary balance sheet details:



	As of December 31, 2017		As of December 31, 2016

(Dollars in thousands)
Inventories:
Raw materials and supplies	$	39,434	$	54,469
Work in process	85,852		52,379
Finished goods	48,865		49,263

	174,151		156,111

Prepaid expenses and other current assets:
Prepaid expenses	$	9,505	$	6,096
Value added tax and other indirect taxes receivable	18,627		12,984
Spare parts inventory	11,010		—
Other current assets	5,730		2,585

	$	44,872	$	21,665

Property, plant and equipment:
Land and improvements	$	46,599	$	43,737
Buildings	59,608		55,440
Machinery and equipment and other	495,069		460,892
Construction in progress	41,375		25,635

	$	642,651	$	585,704

Other accrued liabilities:
Payrolls (including incentive programs)	$	14,196	$	4,802
Employee benefits	4,684		11,439
Customer prepayments	20,784		—
Other	13,562		14,278

	$	53,226	$	30,519

Other long term obligations:
Postretirement benefits	$	20,508	$	19,002
Pension and related benefits	36,116		45,876
Other	12,283		17,270

	$	68,907	$	82,148

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



	2017		2016			For the period August 15 through December 31, 2015		For the period January 1 through August 14, 2015

	(Dollars in thousands)
Balance at beginning of year	$	326	$	244		$	—	$	6,969
Additions	771		129			244		85
Deductions	—		(47		)	—		(1,177		)

Balance at end of year	$	1,097	$	326		$	244	$	5,877