CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net (loss) income	$ (70,513)	$ 34,944	$ 49,317
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Gain on divestiture	(1,459)	0	0
Depreciation and amortization	49,000	33,162	26,130
Impairment of goodwill and long-lived assets	64,206	0	772
Deferred income taxes	(14,585)	636	(2,933)
Employee benefit plans settlement expenses	25,247	0	0
Stock-based compensation	2,829	2,081	4,269
Inventory step-up amortization	0	1,975	1,108
(Gain) loss on disposition of property, plant and equipment	(17)	230	0
(Income) loss from equity method investment	(148)	(132)	28
Changes in operating assets and liabilities:
Accounts receivable	37,470	(7,127)	(8,046)
Contract assets	(5,514)	(3,828)	0
Inventories	2,619	(6,001)	(11,116)
Taxes receivable	(876)	3,151	(1,216)
Prepaid expenses and other assets	2,031	(542)	(784)
Accounts payable	(393)	(5,055)	14,315
Accrued payroll and other compensation	4,597	(2,352)	1,103
Deferred revenue	(4,267)	3,801	934
Accrued taxes	2,500	535	(4,708)
Benefit plan liabilities	(4,288)	(7,658)	(5,245)
Other, net	(1,577)	(3,081)	(992)
Net cash provided by operating activities	86,862	44,739	62,936
Cash flows from investing activities:
Capital expenditures	(35,850)	(31,291)	(27,006)
Proceeds from the sale of property, plant and equipment	298	298	0
Proceeds from divestiture	2,298	0	0
Business acquisitions, net of cash acquired	869	(269,972)	(323)
Net cash used for investing activities	(32,385)	(300,965)	(27,329)
Cash flows from financing activities:
Proceeds from borrowings	0	338,000	0
Debt repayments	(52,233)	(89,862)	(51,762)
Debt issuance cost repayments	0	(538)	0
Common stock issued	448	850	1,323
Common stock repurchased	(142)	(974)	(2,770)
Net cash (used for) provided by financing activities	(51,927)	247,476	(53,209)
Effect of exchange rate changes on cash	(456)	(1,888)	5,543
Increase (decrease) in cash and cash equivalents	2,094	(10,638)	(12,059)
Cash and cash equivalents at beginning of period	49,237	59,875	71,934
Cash and cash equivalents at end of period	51,331	49,237	59,875
Cash paid during the year for:
Interest	14,064	5,960	2,747
Income taxes, net	5,863	4,606	16,158
Non-cash capital expenditures	$ 5,500	$ 4,900	$ 6,500