Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 95,852	$ 183,284
Trade receivables, less allowances of $667 and $1,061 at respective dates	146,330	75,144
Contract assets	33,490
Other receivables	5,198	20,891
Inventories, net	111,062	138,542
Prepaid expenses and other current assets	18,160	4,217
Total current assets	410,092	422,078
Property, plant and equipment, net	360,528	254,299
Goodwill	261,095	43,626
Intangible assets, net	187,205	13,868
Deferred income taxes	1,409	3,198
Other non-current assets	3,099	3,496
Total assets	1,223,428	740,565
Current liabilities:
Accounts payable	47,012	35,017
Contract liabilities, current	11,713	4,707
Taxes payable	1,651	43
Accrued expenses and other current liabilities	44,036	42,774
Total current liabilities	104,412	82,541
Long-term debt	300,000
Contract liabilities, non-current	42,701	39,000
Deferred income taxes	57,276	7,806
Accrued pension benefits	42,218	41,141
Other non-current liabilities	23,094	25,213
Total liabilities	569,701	195,701
Commitments and contingencies (see Notes 20 and 21)
Stockholders' equity:
Common Stock, $.10 par value; authorized 100,000,000 issued 34,870,124 and 34,270,975 shares at respective dates	3,487	3,427
Additional paid-in capital	182,691	165,979
Retained earnings	538,463	429,826
Treasury stock, at cost, 1,264,109 and 1,424,153 shares at respective dates	(10,777)	(12,140)
Accumulated other comprehensive loss	(60,137)	(42,228)
Total stockholders' equity	653,727	544,864
Total liabilities and stockholders' equity	$ 1,223,428	$ 740,565