Weighted Average Shares Outstanding (Schedule of Weighted Average Shares Outstanding) (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Basic shares outstanding (in shares)	104.7	104.0	104.5	103.8
Effect of potential common stock:
Common stock awards (in shares)	1.2	1.2	1.1	1.2
Diluted shares outstanding (in shares)	105.9	105.2	105.6	105.0