Fair Value Measurements (Details 6) (Contingent consideration, USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2014 Minimum	Jun. 30, 2014 Maximum
Changes in Level 3 liabilities measured at fair value on recurring basis
Beginning balance	$ 48,395	$ 46,022	$ 44,004	$ 42,624
Fair value adjustments included in other income (expense), net	2,162	3,404	3,914	1,380
Contingent consideration settled	(229)	(1,031)
Ending balance	$ 50,238	$ 48,395	$ 47,918	$ 44,004
Fair value inputs, discount rate (as a percent)					14.00%	18.00%

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

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-Name Accounting Standards Codification

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-Section 50

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

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-Section 50

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-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

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-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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