Shareholders' Equity and Noncontrolling Interests, Stock Repurchase (Details) - USD ($) shares in Millions, $ in Millions		1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 24, 2018	Oct. 20, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Shareholders' Equity
Treasury stock retired (in dollars)			$ 0.0	$ 0.0	$ 0.0	$ 0.0
Payments for shares repurchased (in dollars)			$ 201.9	$ 150.0	$ 459.2	$ 558.7
2018 Stock Repurchase Program
Shareholders' Equity
Value of shares authorized to be repurchased (in dollars)	$ 2,000.0
Repurchase of stock program, period	3 years
Number of shares repurchased			1.9	1.7	4.6	6.1
Payments for shares repurchased (in dollars)			$ 201.9	$ 150.0	$ 459.2	$ 558.7
Number of treasury shares retired					3.6	5.1
Treasury stock retired (in dollars)					$ 348.9	$ 471.1
Number of shares repurchased and retained in treasury					1.0	1.0
Payments for shares repurchased (in dollars)					$ 110.3	$ 87.6
Subsequent Event | 2018 Stock Repurchase Program
Shareholders' Equity
Number of shares repurchased and retained in treasury		0.1
Payments for shares repurchased (in dollars)		$ 6.0
Value of shares remaining that may be repurchased under the stock repurchase program (in dollars)		$ 379.9