Consolidated Statement of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 58,851	$ 50,240	$ 48,223
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	12,339	12,252	11,455
Amortization	3,445	3,106	2,338
Equity in undistributed earnings of associated companies, net of dividends	(4,162)	(2,350)	(2,365)
Deferred income taxes	(30)	2,354	2,431
Uncertain tax positions (non-deferred portion)	(1,826)	(1,407)	3,673
Acquisition-related Fair Value Adjustments	200	(1,909)	(2,624)
Deferred compensation and other, net	(259)	(156)	566
Stock-based compensation	4,161	3,807	3,513
Loss (Gain) on disposal of property, plant and equipment	200	(108)	(86)
Insurance settlement realized	(988)	(1,391)	(1,840)
Pension and other postretirement benefits	862	(1,427)	(4,239)
(Decrease) increase in cash from changes in current assets and current liabilities, net of acquisitions:
Accounts receivable	(11,837)	779	(31,558)
Inventories	406	3,228	(9,281)
Prepaid expenses and other current assets	(743)	504	(2,505)
Accounts payable and accrued liabilities	11,301	(2,562)	4,442
Estimated taxes on income	1,881	(2,067)	(2,477)
Net cash provided by operating activities	73,801	62,893	19,666
Cash flows from investing activities
Capital Expenditures	(11,439)	(12,735)	(12,117)
Payments related to acquisitions, net of cash acquired	(2,478)	(5,635)	(25,477)
Proceeds from disposition of assets	513	245	393
Insurance settlement received and interest earned	52	69	80
Change in restricted cash, net	936	1,322	1,760
Net cash used in investing activities	(12,416)	(16,734)	(35,361)
Cash flows from financing activities
Net decrease in short-term borrowings	0	(315)	(254)
Proceeds from long-term debt	0	0	0
Repayment of long-term debt	(12,791)	(17,632)	(27,364)
Dividends paid	(13,018)	(12,616)	(11,586)
Stock options exercised, other	(307)	(924)	1,105
Excess tax benefit from stock option exercises	815	2,045	109
Proceeds from Issuance of Common Stock	0	0	48,143
Dividends Paid to Noncontrolling Shareholders	(905)	(1,099)	(1,000)
Net cash (used in) provided by financing activities	(26,206)	(30,541)	9,153
Effect of exchange rate changes on cash	766	20	(2,315)
Net increase (decrease) in cash and cash equivalents	35,945	15,638	(8,857)
Cash and cash equivalents at beginning of period	32,547	16,909	25,766
Cash and cash equivalents at end of period	68,492	32,547	16,909
Supplemental Cash Flow Information [Abstract]
Income Taxes Paid	17,744	13,190	9,110
Interest Paid	1,776	2,809	3,298
Other Noncash Investing And Financing Items [Abstract]
Accrued Purchases of Property, Plant and Equipment	$ 1,287	$ 0	$ 0