Proforma Effect in Net Revenue, Net Income and Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2013 Clinical Trial Services	Dec. 31, 2012 Clinical Trial Services	Dec. 31, 2012 PriceSpective LLC	Dec. 31, 2011 PriceSpective LLC	Dec. 31, 2012 BeijingWits Medical Limited	Dec. 31, 2011 BeijingWits Medical Limited	Dec. 31, 2011 Firecrest Clinical Limited	Dec. 31, 2010 Firecrest Clinical Limited
Business Acquisition [Line Items]
Net revenue	$ 1,343,996	$ 1,182,734	$ 1,118,410	$ 964,388	$ 1,115,355	$ 989,942	$ 952,729	$ 906,311
Net income	$ 103,133	$ 58,944	$ 55,931	$ 25,363	$ 55,349	$ 22,549	$ 25,851	$ 86,127
Basic earnings per share	$ 1.69	$ 0.98	$ 0.93	$ 0.42	$ 0.92	$ 0.37	$ 0.43	$ 1.44
Diluted earnings per share	$ 1.66	$ 0.98	$ 0.93	$ 0.42	$ 0.92	$ 0.37	$ 0.42	$ 1.42

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

+ Details

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

+ Details

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- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

+ Details

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