Related Party Transactions - Summary of Related Party Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Related Party Transaction [Line Items]
Total related party expenses	$ 357	$ 269
Pharmacovigilance Services [Member] | INC Research Holdings, Inc. [Member]
Related Party Transaction [Line Items]
Total related party expenses	0	166
Avista [Member] | Offering Costs Paid Pursuant to Registration Rights Agreement [Member]
Related Party Transaction [Line Items]
Total related party expenses	149	0
VWR Scientific [Member] | Inventory Supplies [Member]
Related Party Transaction [Line Items]
Total related party expenses	$ 208	$ 103