Stockholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 29, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Oct. 27, 2020	Jul. 28, 2020	Oct. 22, 2019	Feb. 28, 2017
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired		0.6	3.1	4.2	3.5
Treasury Stock, Value, Acquired, Cost Method		$ 73.5	$ 334.6	$ 434.3	$ 383.5
Common Stock
Class of Stock [Line Items]
Repurchase authorization amount							$ 1,500.0	$ 1,000.0	$ 1,000.0
Subsequent Event | Common Stock
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired	0.4
Treasury Stock, Value, Acquired, Cost Method	$ 45.2
Remaining authorized repurchase amount						$ 2,055.9