Earnings Per Share (Narrative) (Details) - shares shares in Millions		12 Months Ended
	May 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Weighted average shares excluded from denominator for diluted earnings per share because the stock options were anti-dilutive		1.2	0.6	0.3
Issuance of common stock under Equity Units stock purchase contracts, shares	6.0
Restricted stock units excluded from the denominator for diluted earnings per share		0.3	0.2	0.3