Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 21, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019	Sep. 30, 2016
Class of Stock [Line Items]
Payments for repurchase of common stock			$ 3,775.2	$ 3,000.0
2019 Share Repurchase Program
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 5,000.0
Repurchase of common stock, at cost, shares		3.1	7.0
Payments for repurchase of common stock		$ 717.9	$ 1,600.0
Amount remaining under 2019 Share Repurchase Program		$ 2,900.0	$ 2,900.0
2018 Share Repurchase Program
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 3,500.0
Repurchase of common stock, at cost, shares			8.9
Payments for repurchase of common stock			$ 2,100.0
2016 Share Repurchase Program
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount						$ 5,000.0
Repurchase of common stock, at cost, shares				10.5
Payments for repurchase of common stock				$ 3,000.0
Subsequent Event [Member] | 2019 Share Repurchase Program
Class of Stock [Line Items]
Repurchase of common stock, at cost, shares	2.3
Payments for repurchase of common stock	$ 508.6