Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011	Dec. 31, 2008
Income before taxes and minority interest
United States	$ 42,429	$ 18,415	$ 70,695
Foreign	20,545	10,083	13,847
Income before income taxes	62,974	28,498	84,542
Current:
Federal	14,369	12,673	21,779
State	876	900	462
Foreign	5,976	3,765	2,896
Current income tax expense (benefit)	21,221	17,338	25,137
Deferred:
Federal	(962)	(8,603)	(1,718)
State	(66)	77	(142)
Foreign	(1,463)	(819)	109
Deferred income tax expense (benefit)	(2,491)	(9,345)	(1,751)
Total income tax expense (benefit)	18,730	7,993	23,386
Reconciliation of income taxes
Income tax expense at U.S. statutory rate	22,041	9,974	29,589
State income taxes, net of federal tax benefit	810	976	319
Foreign income (loss), net of credit on foreign taxes	137	176	(31)
Effective tax rate differential of earnings outside of U.S.	(1,901)	(1,221)	(1,455)
Foreign investment tax credit	(777)	(305)	(385)
Non-taxable gain on acquisiton of business	0	(394)	(2,434)
Non-deductible (taxable) items	74	(144)	(735)
(Income) provision for tax contingencies	(28)	2	(69)
Domestic production activities deduction	(1,626)	(1,071)	(1,413)
Deferred tax assets:
Accruals and reserves	14,036	13,699
Pensions	5,562	4,245
Inventory	1,630	1,363
Stock options	4,539	5,412
Tax credit carryforwards	1,070	594
Foreign net operating loss carryforwards	1,405	861
Federal net operating loss carryforward	0	10,189
State net operating loss carryforward	1,442	947
Other - net	1,138	1,279
Total deferred tax assets before valuation allowance	30,822	38,589
Valuation allowance	(1,869)	(758)
Total deferred tax assets, net of valuation allowance	28,953	37,831
Deferred tax liabilities:
Property, plant and equipment	16,392	11,973
Intangibles	38,888	52,312
Convertible notes	3,613	0
Total deferred tax liabilities	58,893	64,285
Net deferred tax liabilities	(29,940)	(26,454)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at beginning of the year				2,440
Additions for tax positions of prior years	128	2,170	22
Reductions for tax positions of prior years	(22)	(22)	(22)
Lapse of statutes of limitation	(134)	(1,150)	(433)
Unrecognized tax benefits at end of the year	2,440	2,468	1,470		1,903
Income Taxes Paid	17,130	15,266	24,659
Accrual for interest and penalties	77
Accrual for additional interest associated with uncertain tax positions	42	50
Possible future decreases in unrecognized tax benefits	$ 1,022