Goodwill and Intangible Assets, Net, Intangible Assets, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount	$ 54,599	$ 54,537	$ 62,577
Accumulated amortization	(27,838)	(25,211)	(31,773)
Net carrying amount	26,761	29,326	30,804
North America
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount	30,715	30,775	33,863
Accumulated amortization	(15,232)	(13,732)	(15,786)
Net carrying amount	15,483	17,043	18,077
Europe
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount	23,884	23,762	28,714
Accumulated amortization	(12,606)	(11,479)	(15,987)
Net carrying amount	$ 11,278	$ 12,283	$ 12,727

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

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

+ References

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- Definition

Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph ((a)(1),(b))
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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