Debt and Commitments (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Fair Value	$ 537,696	$ 504,528
Borrowings under lines of credit and overdrafts	5,669	30,825
Total debt, net of unamortized discounts	532,596	500,954
Less current maturities	(6,999)	(32,892)
Long-term debt	525,597	468,062
Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Carrying Amount	421,500	363,300
Fair Value	424,818	364,775
Senior Notes [Member] \| 3.97% Senior Notes [Member]
Debt Instrument [Line Items]
Carrying Amount	100,000	100,000
Fair Value	101,348	101,598
Lines of credit and overdrafts [Member]
Debt Instrument [Line Items]
Fair Value	5,669	30,825
Borrowings under lines of credit and overdrafts	5,669	30,825
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Carrying Amount	4,541	5,413
Fair Value	4,964	5,902
Foreign bank borrowings [Member]
Debt Instrument [Line Items]
Carrying Amount	886	1,416
Fair Value	$ 897	$ 1,428

Total debt, net of unamortized discounts

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- Definition

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

+ References

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
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-Subparagraph (a)
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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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