Income Taxes (Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Unrecognized tax benefits balance at January 1	$ 4,183	$ 19,606	$ 19,509
Increase in gross amounts of tax positions related to prior years	480	62	2,315
Decrease in gross amounts of tax positions related to prior years	(50)	(2,129)	(145)
Increase in gross amounts of tax positions related to current year		585	79
Decrease due to settlements with tax authorities	(381)	(14,029)	(42)
Decrease due to lapse in statute of limitations	(29)	(163)	(90)
Currency translation	306	251
Currency translation			(2,020)
Unrecognized tax benefits balance at December 31	$ 4,509	$ 4,183	$ 19,606

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Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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