Weighted Average Shares Outstanding (Schedule of Weighted Average Shares Outstanding) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Basic shares outstanding (in shares)	104.5	103.9	104.4	103.7
Effect of potential common stock:
Common stock awards (in shares)	1.0	1.2	1.0	1.2
Diluted shares outstanding (in shares)	105.5	105.1	105.4	104.9