Guarantor Financial Information - Schedule of Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Income Statements, Captions [Line Items]
Net revenues	$ 489,417	$ 449,569	$ 940,394	$ 871,374
Reimbursed out-of-pocket expenses	83,077	64,042	150,400	120,355
Total revenues	572,494	513,611	1,090,794	991,729
Operating expenses:
Cost of revenues	318,390	292,712	609,567	566,970
Reimbursable out-of-pocket expenses	83,077	64,042	150,400	120,355
Selling, general and administrative expenses	141,395	145,215	283,637	284,336
Total operating expenses	542,862	501,969	1,043,604	971,661
Operating income (loss)	29,632	11,642	47,190	20,068
Interest income (expense), net	(57,120)	(53,232)	(113,583)	(105,684)
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	(27,488)	(41,590)	(66,393)	(85,616)
Income tax (provision) benefit	(2,738)	(5,753)	(7,266)	(7,698)
Income (loss) before income (loss) from equity investments	(30,226)	(47,343)	(73,659)	(93,314)
Income (loss) from equity investments	238	(198)	(1,291)	(236)
Income (loss) from continuing operations	(29,988)	(47,541)	(74,950)	(93,550)
Net income (loss) from discontinued operations, net of tax		(5,453)		(8,163)
Net income (loss)	(29,988)	(52,994)	(74,950)	(101,713)
Less: Net (income) loss attributable to the noncontrolling interest	(243)	6	(366)	(520)
Net income (loss) attributable to inVentiv Health, Inc.	(30,231)	(52,988)	(75,316)	(102,233)
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net revenues	(6,418)	(11,958)	(12,173)	(25,362)
Reimbursed out-of-pocket expenses	(62)	(31)	(138)	(241)
Total revenues	(6,480)	(11,989)	(12,311)	(25,603)
Operating expenses:
Cost of revenues	(5,885)	(11,394)	(11,147)	(24,098)
Reimbursable out-of-pocket expenses	(62)	(31)	(138)	(241)
Selling, general and administrative expenses	(533)	(564)	(1,026)	(1,264)
Total operating expenses	(6,480)	(11,989)	(12,311)	(25,603)
Income (loss) from equity investments	(12,655)	25,376	(10,467)	41,000
Income (loss) from continuing operations		25,376		41,000
Net income (loss)	(12,655)	25,376	(10,467)	41,000
Net income (loss) attributable to inVentiv Health, Inc.	(12,655)	25,376	(10,467)	41,000
Inventiv Health Inc [Member]
Operating expenses:
Selling, general and administrative expenses	20,491	9,262	36,578	17,801
Allocation of intercompany costs	(9,900)	(11,715)	(19,800)	(23,486)
Total operating expenses	10,591	(2,453)	16,778	(5,685)
Operating income (loss)	(10,591)	2,453	(16,778)	5,685
Interest income (expense), net	(57,088)	(53,287)	(113,444)	(105,719)
Intercompany interest income (expense)	23,579	21,885	46,384	43,067
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	(44,100)	(28,949)	(83,838)	(56,967)
Income tax (provision) benefit				(127)
Income (loss) before income (loss) from equity investments	(44,100)	(28,949)	(83,838)	(57,094)
Income (loss) from equity investments	13,869	(24,039)	8,522	(45,139)
Income (loss) from continuing operations		(52,988)		(102,233)
Net income (loss)	(30,231)	(52,988)	(75,316)	(102,233)
Net income (loss) attributable to inVentiv Health, Inc.	(30,231)	(52,988)	(75,316)	(102,233)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net revenues	382,908	332,133	729,889	642,855
Reimbursed out-of-pocket expenses	68,450	51,271	128,066	94,064
Total revenues	451,358	383,404	857,955	736,919
Operating expenses:
Cost of revenues	249,948	219,961	479,030	428,244
Reimbursable out-of-pocket expenses	68,450	51,271	128,066	94,064
Selling, general and administrative expenses	85,823	97,707	177,743	192,601
Allocation of intercompany costs	7,935	8,897	15,879	17,893
Total operating expenses	412,156	377,836	800,718	732,802
Operating income (loss)	39,202	5,568	57,237	4,117
Interest income (expense), net	(197)	(114)	(408)	(208)
Intercompany interest income (expense)	(23,332)	(21,230)	(45,987)	(41,736)
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	15,673	(15,776)	10,842	(37,827)
Income tax (provision) benefit	(1,650)	(3,578)	(4,625)	(5,691)
Income (loss) before income (loss) from equity investments	14,023	(19,354)	6,217	(43,518)
Income (loss) from equity investments	(976)	(1,535)	654	3,903
Income (loss) from continuing operations		(20,889)		(39,615)
Net income (loss) from discontinued operations, net of tax		(5,453)		(8,163)
Net income (loss)	13,047	(26,342)	6,871	(47,778)
Net income (loss) attributable to inVentiv Health, Inc.	13,047	(26,342)	6,871	(47,778)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net revenues	112,927	129,394	222,678	253,881
Reimbursed out-of-pocket expenses	14,689	12,802	22,472	26,532
Total revenues	127,616	142,196	245,150	280,413
Operating expenses:
Cost of revenues	74,327	84,145	141,684	162,824
Reimbursable out-of-pocket expenses	14,689	12,802	22,472	26,532
Selling, general and administrative expenses	35,614	38,810	70,342	75,198
Allocation of intercompany costs	1,965	2,818	3,921	5,593
Total operating expenses	126,595	138,575	238,419	270,147
Operating income (loss)	1,021	3,621	6,731	10,266
Interest income (expense), net	165	169	269	243
Intercompany interest income (expense)	(247)	(655)	(397)	(1,331)
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	939	3,135	6,603	9,178
Income tax (provision) benefit	(1,088)	(2,175)	(2,641)	(1,880)
Income (loss) before income (loss) from equity investments	(149)	960	3,962	7,298
Income (loss) from continuing operations		960		7,298
Net income (loss)	(149)	960	3,962	7,298
Less: Net (income) loss attributable to the noncontrolling interest	(243)	6	(366)	(520)
Net income (loss) attributable to inVentiv Health, Inc.	$ (392)	$ 966	$ 3,596	$ 6,778