Goodwill and Intangible Assets (Goodwill) (Details) $ in Thousands	6 Months Ended
Jun. 30, 2017 USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2016	$ 74,825
Goodwill acquired	6,301
Translation adjustments	1,304
Balance at June 30, 2017	$ 82,430
Goodwill \| Total assets
Goodwill [Roll Forward]
Percentage of total assets	12.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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