CONSOLIDATED STATEMENTS OF CASH FLOW (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
OPERATING ACTIVITIES
Net income	$ 15,220	$ 13,409	$ 27,427	$ 36,826
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	15,522	16,470	45,367	44,736
Amortization	2,608	1,975	7,889	6,488
Change in other noncurrent liabilities	(168)	(275)	(2,522)	(5,010)
Change in deferred taxes and other liabilities	(3,263)	(1,712)	(10,620)	(640)
Provision for write-off of property, plant and equipment	1,086	333	1,916	1,409
Non-cash interest expense	211		634
Compensation and benefits paid or payable in Class A Common Stock	195	350	1,865	1,882
Write-off of intangible assets in a discontinued product line	4,149		4,149
Changes in operating assets and liabilities that provided/(used) cash, net of impact of business acquisition:
Accounts receivable	(4,645)	4,794	(19,781)	(6,492)
Inventories	(3,944)	(5,511)	(17,210)	(12,886)
Prepaid expenses and other current assets	(599)	(481)	(3,167)	(3,302)
Income taxes prepaid and receivable		(100)	(2,817)	1,737
Accounts payable	(4,769)	(4,443)	(2,704)	(1,544)
Accrued liabilities	5,425	4,418	4,525	(3,736)
Income taxes payable	3,472	4,932	2,964	3,999
Contract receivables	(8,107)		(15,643)
Other, net	(4,495)	(4,974)	(557)	(10,252)
Net cash provided by operating activities	17,898	29,185	21,715	53,215
INVESTING ACTIVITIES
Purchase of business, net of cash acquired				(187,000)
Purchases of property, plant and equipment	(15,319)	(21,924)	(61,724)	(50,029)
Purchased software	(147)	(591)	(538)	(1,262)
Proceeds from sale or involuntary conversion of assets		4,686		6,422
Net cash used in investing activities	(15,466)	(17,829)	(62,262)	(231,869)
FINANCING ACTIVITIES
Proceeds from borrowings	13,076	13,265	45,335	232,795
Principal payments on debt	(3,569)	(871)	(24,711)	(23,695)
Debt acquisition costs				(1,771)
Swap termination payment				(5,175)
Taxes paid in lieu of share issuance			(1,364)	(1,272)
Proceeds from options exercised	356	64	531	454
Dividends paid	(5,470)	(5,457)	(16,396)	(16,354)
Net cash provided by financing activities	4,393	7,001	3,395	184,982
Effect of exchange rate changes on cash and cash equivalents	7,848	1,788	8,875	4,729
(Decrease)/increase in cash and cash equivalents	14,673	20,145	(28,277)	11,057
Cash and cash equivalents at beginning of period	138,792	176,025	181,742	185,113
Cash and cash equivalents at end of period	$ 153,465	$ 196,170	$ 153,465	$ 196,170