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Acquisitions Schedule of Intangible Assets Acquired as Part of Business Combination (Details) - USD ($) $ in Thousands | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2016 | Jun. 05, 2015 | Apr. 14, 2015
Creative Circle [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  | $ 194,500 |
Creative Circle [Member] | Trademarks [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  | 66,100 |
Creative Circle [Member] | Contractor Relations [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  | 29,500 |
Creative Circle [Member] | Customer relations |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  | 90,700 |
Creative Circle [Member] | Non-compete agreements |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  | 7,300 |
Creative Circle [Member] | Contract-Based Intangible Assets [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  | $ 900 |
LabResource [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  | $ 7,528
LabResource [Member] | Trademarks [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  | 1,140
LabResource [Member] | Contractor Relations [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  | 947
LabResource [Member] | Customer relations |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  | 5,421
LabResource [Member] | Non-compete agreements |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  | 20
LabResource [Member] | Contract-Based Intangible Assets [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill |  |  | $ 0
Minimum [Member] | Contractor Relations [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 2 years |  |
Minimum [Member] | Customer relations |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 2 years |  |
Minimum [Member] | Non-compete agreements |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 2 years |  |
Minimum [Member] | Contract-Based Intangible Assets [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 5 years |  |
Minimum [Member] | Computer Software, Intangible Asset [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 6 years |  |
Maximum [Member] | Contractor Relations [Member] |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 4 years |  |
Maximum [Member] | Customer relations |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 10 years |  |
Maximum [Member] | Non-compete agreements |  |  |
Acquired Intangible Assets [Line Items] |  |  |
Acquired Finite Lived Intangible Assets Average Useful Life | 6 years |  |

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- Definition Amount of intangible assets, excluding goodwill, acquired at the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4845-128472 + Details
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