Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Payments for repurchase of common stock		$ 5,029.1	$ 3,057.3
December 2019 Share Repurchase Program
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 5,000.0
Repurchase of common stock, at cost, shares	9.0	12.2
Payments for repurchase of common stock	$ 2,800.0	$ 3,700.0
2019 Share Repurchase Program
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount			$ 5,000.0
Repurchase of common stock, at cost, shares		4.1
Payments for repurchase of common stock		$ 1,300.0
Amount remaining under 2019 Share Repurchase Program	$ 1,300.0	$ 1,300.0