Guarantor Financial Information - Condensed Consolidating Balance Sheet Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 77,113	$ 121,317	$ 38,653	$ 57,059
Restricted cash	2,554	1,607
Accounts receivable, net of allowances for doubtful accounts	328,326	359,081
Unbilled services	261,723	207,465
Prepaid expenses and other current assets	45,059	42,930
Income tax receivable	1,022	1,076
Total current assets	715,797	733,476
Property and equipment, net	139,172	142,032
Goodwill	896,765	895,369
Intangible assets, net	325,919	334,646
Non-current deferred tax assets	10,421	10,032
Other assets	39,721	37,134
Total assets	2,127,795	2,152,689
Current liabilities:
Current portion of capital lease obligations and other financing arrangements	25,296	23,333
Accrued payroll, accounts payable and accrued expenses	318,948	333,726
Income taxes payable	3,829	5,484
Deferred revenue and client advances	246,621	246,656
Total current liabilities	594,694	609,199
Capital lease obligations, net of current portion	45,525	45,258
Long-term debt, net of current portion	2,117,132	2,101,885
Non-current income tax liability	7,567	5,942
Deferred tax liability	79,106	73,360
Other non-current liabilities	66,750	88,153
Total liabilities	2,910,774	2,923,797
Total inVentiv Health, Inc. stockholder’s deficit	(784,977)	(772,736)
Noncontrolling interest	1,998	1,628
Total stockholder’s deficit	(782,979)	(771,108)
Total liabilities and stockholder’s deficit	2,127,795	2,152,689
Eliminations [Member]
Current assets:
Cash and cash equivalents	(87,289)	(82,879)	(86,134)	(52,037)
Intercompany receivables	(1,414,950)	(1,388,167)
Income tax receivable		(104)
Total current assets	(1,502,239)	(1,471,150)
Non-current intercompany receivables	(458,035)	(480,417)
Investment in consolidated subsidiaries	(807,813)	(769,670)
Total assets	(2,768,087)	(2,721,237)
Current liabilities:
Current portion of capital lease obligations and other financing arrangements	(79,229)	(73,282)
Accrued payroll, accounts payable and accrued expenses	(8,060)	(9,597)
Intercompany payables	(1,414,950)	(1,388,167)
Income taxes payable		(104)
Total current liabilities	(1,502,239)	(1,471,150)
Non-current intercompany liabilities	(458,035)	(480,417)
Total liabilities	(1,960,274)	(1,951,567)
Total inVentiv Health, Inc. stockholder’s deficit	(807,813)	(769,670)
Total stockholder’s deficit	(807,813)	(769,670)
Total liabilities and stockholder’s deficit	(2,768,087)	(2,721,237)
Inventiv Health Inc [Member]
Current assets:
Cash and cash equivalents	27,758	55,226	27,622	19,643
Restricted cash	1,716	226
Intercompany receivables	504,621	529,457
Prepaid expenses and other current assets	7,364	8,839
Income tax receivable	26	104
Total current assets	541,485	593,852
Property and equipment, net	21,369	23,227
Other assets	20,331	19,084
Non-current intercompany receivables	429,168	416,161
Investment in consolidated subsidiaries	700,686	676,479
Total assets	1,713,039	1,728,803
Current liabilities:
Current portion of capital lease obligations and other financing arrangements	1,429	1,936
Accrued payroll, accounts payable and accrued expenses	78,168	71,953
Intercompany payables	857,790	820,965
Total current liabilities	937,387	894,854
Long-term debt, net of current portion	1,547,653	1,533,197
Deferred tax liability	74	74
Other non-current liabilities	12,902	38,494
Non-current intercompany liabilities		34,920
Total liabilities	2,498,016	2,501,539
Total inVentiv Health, Inc. stockholder’s deficit	(784,977)	(772,736)
Total stockholder’s deficit	(784,977)	(772,736)
Total liabilities and stockholder’s deficit	1,713,039	1,728,803
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents				3,439
Accounts receivable, net of allowances for doubtful accounts	266,930	292,548
Unbilled services	223,422	174,070
Intercompany receivables	825,469	840,499
Prepaid expenses and other current assets	19,001	11,401
Total current assets	1,334,822	1,318,518
Property and equipment, net	98,916	101,507
Goodwill	855,317	855,317
Intangible assets, net	319,311	328,239
Other assets	4,330	4,491
Non-current intercompany receivables	28,867	29,235
Investment in consolidated subsidiaries	107,127	93,191
Total assets	2,748,690	2,730,498
Current liabilities:
Current portion of capital lease obligations and other financing arrangements	23,831	21,324
Accrued payroll, accounts payable and accrued expenses	182,536	200,063
Intercompany payables	537,244	542,500
Income taxes payable	449	165
Deferred revenue and client advances	189,789	190,828
Total current liabilities	933,849	954,880
Capital lease obligations, net of current portion	45,512	45,247
Long-term debt, net of current portion	569,479	568,688
Non-current income tax liability	4,807	4,806
Deferred tax liability	77,854	73,047
Other non-current liabilities	31,599	30,896
Non-current intercompany liabilities	429,157	416,260
Total liabilities	2,092,257	2,093,824
Total inVentiv Health, Inc. stockholder’s deficit	656,433	636,674
Total stockholder’s deficit	656,433	636,674
Total liabilities and stockholder’s deficit	2,748,690	2,730,498
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	136,644	148,970	$ 97,165	$ 86,014
Restricted cash	838	1,381
Accounts receivable, net of allowances for doubtful accounts	61,396	66,533
Unbilled services	38,301	33,395
Intercompany receivables	84,860	18,211
Prepaid expenses and other current assets	18,694	22,690
Income tax receivable	996	1,076
Total current assets	341,729	292,256
Property and equipment, net	18,887	17,298
Goodwill	41,448	40,052
Intangible assets, net	6,608	6,407
Non-current deferred tax assets	10,421	10,032
Other assets	15,060	13,559
Non-current intercompany receivables		35,021
Total assets	434,153	414,625
Current liabilities:
Current portion of capital lease obligations and other financing arrangements	79,265	73,355
Accrued payroll, accounts payable and accrued expenses	66,304	71,307
Intercompany payables	19,916	24,702
Income taxes payable	3,380	5,423
Deferred revenue and client advances	56,832	55,828
Total current liabilities	225,697	230,615
Capital lease obligations, net of current portion	13	11
Non-current income tax liability	2,760	1,136
Deferred tax liability	1,178	239
Other non-current liabilities	22,249	18,763
Non-current intercompany liabilities	28,878	29,237
Total liabilities	280,775	280,001
Total inVentiv Health, Inc. stockholder’s deficit	151,380	132,996
Noncontrolling interest	1,998	1,628
Total stockholder’s deficit	153,378	134,624
Total liabilities and stockholder’s deficit	$ 434,153	$ 414,625