Earnings Per Share Components of Basic and Diluted Shares Used In EPS Calculation (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Anti-dilutive shares	0.0	0.1	0.0	0.1
Weighted-average basic common shares outstanding	240.5	217.7	240.4	203.7
Potential number of shares issuable upon exercise of in-the-money stock options under the Long-term Stock Incentive Plan	0.1	0.0	0.1	0.0
Average diluted common shares outstanding	240.6	217.7	240.5	203.7