Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, beginning of year	$ 396,245us-gaap_Goodwill	$ 392,882us-gaap_Goodwill	$ 391,498us-gaap_Goodwill
Additions	25,159us-gaap_GoodwillAcquiredDuringPeriod
Foreign currency translation	(5,468)us-gaap_GoodwillTranslationAdjustments	3,363us-gaap_GoodwillTranslationAdjustments	1,384us-gaap_GoodwillTranslationAdjustments
Goodwill, end of year	415,936us-gaap_Goodwill	396,245us-gaap_Goodwill	392,882us-gaap_Goodwill
Intangible assets with an indefinite life, beginning of year	15,366	15,366	15,366
Intangible assets with an indefinite life, end of year	15,366	15,366	15,366
Intangible assets with a definite life, beginning of year	0us-gaap_FiniteLivedIntangibleAssetsNet	279us-gaap_FiniteLivedIntangibleAssetsNet	457us-gaap_FiniteLivedIntangibleAssetsNet
Additions	18,500
Amortization	(1,850)us-gaap_AmortizationOfIntangibleAssets	(279)us-gaap_AmortizationOfIntangibleAssets	(178)us-gaap_AmortizationOfIntangibleAssets
Intangible assets with a definite life, end of year	16,650us-gaap_FiniteLivedIntangibleAssetsNet	0us-gaap_FiniteLivedIntangibleAssetsNet	279us-gaap_FiniteLivedIntangibleAssetsNet
Goodwill and other intangible assets, beginning of year	411,611	408,527	407,321
Additions	43,659
Goodwill and other intangible assets, end of year	$ 447,952	$ 411,611	$ 408,527

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination.

+ References

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

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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 increase (decrease) from foreign currency translation adjustments 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 assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

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Intangible Assets Including Goodwill Acquired During Period

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