Guarantor Financial Information - Consolidating Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed Income Statements Captions [Line Items]
Net revenues	$ 541,296	$ 450,977
Reimbursed out-of-pocket expenses	90,983	67,323
Total revenues	632,279	518,300
Operating expenses:
Cost of revenues	372,376	300,505
Reimbursable out-of-pocket expenses	90,983	67,323
Selling, general and administrative expenses	123,756	132,914
Total operating expenses	587,115	500,742
Operating income (loss)	45,164	17,558
Gain on extinguishment of debt	221
Interest income (expense), net	(55,853)	(56,463)
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	(10,468)	(38,905)
Income tax (provision) benefit	(8,176)	(4,528)
Income (loss) before income (loss) from equity investments	(18,644)	(43,433)
Income (loss) from equity investments	5	(1,529)
Net income (loss)	(18,639)	(44,962)
Less: Net (income) loss attributable to the noncontrolling interest	(438)	(123)
Net income (loss) attributable to inVentiv Health, Inc.	(19,077)	(45,085)
Eliminations [Member]
Condensed Income Statements Captions [Line Items]
Net revenues	(7,973)	(5,755)
Reimbursed out-of-pocket expenses	(49)	(76)
Total revenues	(8,022)	(5,831)
Operating expenses:
Cost of revenues	(7,314)	(5,262)
Reimbursable out-of-pocket expenses	(49)	(76)
Selling, general and administrative expenses	(659)	(493)
Total operating expenses	(8,022)	(5,831)
Income (loss) from equity investments	(29,357)	2,463
Net income (loss)	(29,357)	2,463
Net income (loss) attributable to inVentiv Health, Inc.	(29,357)	2,463
Inventiv Health Inc [Member]
Operating expenses:
Selling, general and administrative expenses	21,129	16,087
Allocation of intercompany costs	(13,899)	(9,900)
Total operating expenses	7,230	6,187
Operating income (loss)	(7,230)	(6,187)
Gain on extinguishment of debt	221
Interest income (expense), net	(43,831)	(44,398)
Intercompany interest income (expense)	12,975	11,122
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	(37,865)	(39,463)
Income (loss) before income (loss) from equity investments	(37,865)	(39,463)
Income (loss) from equity investments	18,788	(5,622)
Net income (loss)	(19,077)	(45,085)
Net income (loss) attributable to inVentiv Health, Inc.	(19,077)	(45,085)
Guarantor Subsidiaries [Member]
Condensed Income Statements Captions [Line Items]
Net revenues	419,336	346,981
Reimbursed out-of-pocket expenses	83,818	59,616
Total revenues	503,154	406,597
Operating expenses:
Cost of revenues	300,392	236,463
Reimbursable out-of-pocket expenses	83,818	59,616
Selling, general and administrative expenses	71,369	84,539
Allocation of intercompany costs	10,915	7,944
Total operating expenses	466,494	388,562
Operating income (loss)	36,660	18,035
Interest income (expense), net	(12,277)	(12,169)
Intercompany interest income (expense)	(12,715)	(10,972)
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	11,668	(5,106)
Income tax (provision) benefit	(5,145)	(2,975)
Income (loss) before income (loss) from equity investments	6,523	(8,081)
Income (loss) from equity investments	10,574	1,630
Net income (loss)	17,097	(6,451)
Net income (loss) attributable to inVentiv Health, Inc.	17,097	(6,451)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements Captions [Line Items]
Net revenues	129,933	109,751
Reimbursed out-of-pocket expenses	7,214	7,783
Total revenues	137,147	117,534
Operating expenses:
Cost of revenues	79,298	69,304
Reimbursable out-of-pocket expenses	7,214	7,783
Selling, general and administrative expenses	31,917	32,781
Allocation of intercompany costs	2,984	1,956
Total operating expenses	121,413	111,824
Operating income (loss)	15,734	5,710
Interest income (expense), net	255	104
Intercompany interest income (expense)	(260)	(150)
Income (loss) before income tax (provision) benefit and income (loss) from equity investments	15,729	5,664
Income tax (provision) benefit	(3,031)	(1,553)
Income (loss) before income (loss) from equity investments	12,698	4,111
Net income (loss)	12,698	4,111
Less: Net (income) loss attributable to the noncontrolling interest	(438)	(123)
Net income (loss) attributable to inVentiv Health, Inc.	$ 12,260	$ 3,988