Business Combinations - Summary of Pro Forma Results (Detail) - IMS Health Holdings, Inc. [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Revenues	$ 1,926	$ 5,775
Reimbursed expenses	360	1,128
Total revenues	2,286	6,903
Net income attributable to Quintiles IMS Holdings, Inc.	$ 82	$ 195
Earnings per share attributable to common stockholders:
Basic	$ 0.34	$ 0.80
Diluted	$ 0.33	$ 0.78