Common Stock Equivalents (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]
Dilutive Effect of Contingently Issuable Shares	0.5	1.8	0.7	1.5