Earnings Per Share And Shareholder's Equity (Details) - USD ($) $ / shares in Units, shares in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2015	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 31, 2018	Oct. 30, 2015
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, period in force	3 years
Stock repurchase program, authorized amount					$ 1,000,000,000.0	$ 2,000,000,000.0
Average repurchase price (in USD per share)		$ 48.28		$ 77.93
Payments for repurchase of equity		$ 164,200,000		$ 400,000,000.0
Common Stock
Equity, Class of Treasury Stock [Line Items]
Repurchases of ordinary shares, shares		3.4	0.0	5.1