Common Stock Equivalents (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]
Dilutive Effect of Contingently Issuable Shares	1.6	1.8	1.0	1.6