Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 59,811	$ 22,300	$ 63,039
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	12,373	12,598	12,557
Amortization	7,341	7,368	7,009
Equity in undistributed earnings of associated companies, net of dividends	2,784	(2,895)	(1,969)
Deferred income taxes	8,197	3,754	5,488
Uncertain tax positions (non-deferred portion)	(89)	(817)	(3,206)
Non-current income taxes payable	(8,181)	15,825	0
Deferred compensation and other, net	2,984	1,074	(424)
Share-based compensation	3,724	4,190	6,349
Restructuring and related activities	0	0	(439)
Loss (gain) on disposal of property, plant and equipment and other assets	(657)	79	(18)
Insurance settlement realized	(1,055)	(762)	(1,023)
Combination related expenses, net of payements	2,727	4,952	503
Pension and other postretirement benefits contributions	(1,392)	(123)	(3,420)
(Decrease) increase in cash from changes in current assets and current liabilities, net of acquisitions:
Accounts receivable	(2,822)	(1,941)	(11,705)
Inventories	(10,548)	(6,135)	(1,870)
Prepaid expenses and other current assets	(1,540)	(2,932)	(703)
Accounts payable and accrued liabilities	190	12,381	14,063
Restructuring liabilities	0	(675)	(5,252)
Estimated taxes on income	4,932	(3,479)	(5,226)
Net cash provided by operating activities	78,779	64,762	73,753
Cash flows from investing activities
Investments in property, plant and equipment	(12,886)	(10,872)	(9,954)
Payments related to acquisitions, net of cash acquired	(500)	(5,363)	(15,024)
Proceeds from disposition of assets	866	1,577	186
Insurance settlement interest earned	162	50	32
Net cash used in investing activities	(12,358)	(14,608)	(24,760)
Cash flows from financing activities
Proceeds from long-term debt	0
Repayment of long-term debt	(26,791)	(2,853)	(14,513)
Dividends paid	(19,319)	(18,613)	(17,625)
Stock options exercised, other	82	(1,956)	(811)
Payments for repurchase of common stock	0	0	(5,859)
Excess tax benefit from stock option exercises	0	0	678
Purchase of noncontrolling interest in affiliates, net	0	(31,787)	0
Distributions to noncontrolling affiliate shareholders	(877)	0	0
Net cash used in financing activities	(46,905)	(55,209)	(38,130)
Effect of exchange rate changes on cash	(6,141)	5,404	(4,089)
Net increase (decrease) in cash, cash equivalents and restricted cash	13,375	349	6,774
Cash, Cash Equivalents and Restricted Cash at the beginning of the period	111,050	110,701	103,927
Cash, Cash Equivalents and Restricted Cash at the end of the period	124,425	111,050	110,701
Supplemental Cash Flow Information [Abstract]
Income Taxes Paid	19,617	21,544	25,043
Interest Paid	2,417	2,767	2,481
Other Noncash Investing And Financing Items [Abstract]
Change in accrued purchases of property, plant and equipment, net	$ 281	$ (240)	$ 363