Organization and Business - Additional Information (Detail) $ in Thousands		3 Months Ended		9 Months Ended
	Aug. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Segment Company Organization	Sep. 30, 2014 USD ($)
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of reportable segments | Segment				2
Number of global pharmaceutical companies | Company				20
Gain on sale of business				$ 11,318
Net revenues		$ 521,410	$ 462,391	$ 1,461,804	$ 1,333,765
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of client organizations | Organization				550
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | inVentiv Patient Access Solutions ("IPAS") [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Net revenues				$ 11,900	$ 11,800
Other Income [Member] | inVentiv Patient Access Solutions ("IPAS") [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Gain on sale of business	$ 11,300