Subsequent Events (Details) - Subsequent Event [Member]	3 Months Ended
	Jun. 30, 2021
2021 Share Repurchase Program
Subsequent Event [Line Items]
Subsequent Event, Description	On April 23, 2021, our Board of Directors approved a new share repurchase program (the "2021 Share Repurchase Program"), which authorizes the Company to repurchase up to $3.75 billion in the aggregate of shares of our common stock, excluding transaction costs. The 2021 Share Repurchase Program is incremental to our current program originally approved in May 2017. The repurchases are to be effectuated in the open market, by block purchase, in privately negotiated transactions, or through other transactions managed by broker-dealers, or any combination thereof. The 2021 Share Repurchase Program will expire on December 31, 2023.
Kantar Health Acquisition [Member]
Subsequent Event [Line Items]
Subsequent Event, Description	On April 1, 2021, we acquired Kantar Health, a division of Kantar Group, for a base cash purchase price of $375 million. Kantar Health provides data, analytics, commercial research, and consulting services to the life sciences industry. The base purchase price is subject to post-closing adjustments for working capital and certain other adjustments, as specified in the Securities Purchase Agreement dated December 16, 2020, as amended.