Consolidated Statement of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 50,240	$ 48,223	$ 34,404
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	12,252	11,455	9,867
Amortization	3,106	2,338	988
Equity in undistributed earnings of associated companies, net of dividends	(2,350)	(2,365)	(294)
Deferred income taxes	2,354	2,431	1,849
Uncertain tax positions (non-deferred portion)	(1,407)	3,673	(1,130)
Acquisition-related Fair Value Adjustments	(1,909)	(2,624)	0
Deferred compensation and other, net	(156)	566	(628)
Stock-based compensation	3,807	3,513	3,096
Gain on disposal of property, plant and equipment	(108)	(86)	32
Insurance settlement realized	(1,391)	(1,840)	(1,640)
Pension and other postretirement benefits	(1,427)	(4,239)	(2,636)
(Decrease) increase in cash from changes in current assets and current liabilities, net of acquisitions:
Accounts receivable	779	(31,558)	(4,469)
Inventories	3,228	(9,281)	(7,153)
Prepaid expenses and other current assets	504	(2,505)	(814)
Accounts payable and accrued liabilities	(2,562)	4,442	5,511
Estimated taxes on income	(2,067)	(2,477)	564
Net cash provided by operating activities	62,893	19,666	37,547
Cash flows from investing activities
Capital expenditures	(12,735)	(12,117)	(9,354)
Payments related to acquisitions, net of cash acquired	(5,635)	(25,477)	(35,909)
Proceeds from disposition of assets	245	393	229
Insurance settlement received and interest earned	69	80	5,122
Change in restricted cash, net	1,322	1,760	(1,124)
Net cash used in investing activities	(16,734)	(35,361)	(41,036)
Cash flows from financing activities
Net decrease in short-term borrowings	(315)	(254)	(1,456)
Proceeds from long-term debt	0	0	9,841
Repayment of long-term debt	(17,632)	(27,364)	(636)
Dividends paid	(12,616)	(11,586)	(10,449)
Stock options exercised, other	(924)	1,105	5,500
Excess tax benefit from stock option exercises	2,045	109	2,558
Proceeds from Issuance of Common Stock	0	48,143	0
Distributions to noncontrolling shareholders	1,099	1,000	1,021
Net cash provided by (used in) financing activities	(30,541)	9,153	4,337
Effect of exchange rate changes on cash	20	(2,315)	(133)
Net (decrease) increase in cash and cash equivalents	15,638	(8,857)	715
Cash and cash equivalents at beginning of period	16,909	25,766	25,051
Cash and cash equivalents at end of period	32,547	16,909	25,766
Supplemental Cash Flow Information [Abstract]
Income Taxes Paid	13,190	9,110	7,799
Interest Paid	2,809	3,298	4,884
Other Noncash Investing And Financing Items [Abstract]
Restricted insurance receivable	0	0	5,000
Property, plant and equipment acquired by capital lease	$ 0	$ 0	$ 848