Debt (Debt Schedule) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Fair value of debt	$ 525,946	$ 537,696
Total debt, net of unamortized discounts	521,084	532,596
Borrowings under lines of credit and overdrafts	14,896	5,669
Less current maturities	(17,904)	(6,999)
Long-term debt	503,180	525,597
Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Carrying amount of debt	397,550	421,500
Fair value of debt	401,436	424,818
Senior Notes [Member] \| 3.97% Senior Notes [Member]
Debt Instrument [Line Items]
Carrying amount of debt	100,000	100,000
Fair value of debt	100,304	101,348
Lines of Credit and Overdrafts [Member]
Debt Instrument [Line Items]
Fair value of debt	14,896	5,669
Borrowings under lines of credit and overdrafts	14,896	5,669
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Carrying amount of debt	7,896	4,541
Fair value of debt	8,555	4,964
Foreign Bank Borrowings [Member]
Debt Instrument [Line Items]
Carrying amount of debt	742	886
Fair value of debt	$ 755	$ 897

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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- Definition

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
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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
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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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
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