Earnings Per Share (Reconciliation of Basic Shares Outstanding to Diluted Shares Outstanding) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Basic shares outstanding	55.6	55.5	55.6	55.4
Dilutive effect of common stock equivalents	0.4	0.3	0.3	0.4
Diluted shares outstanding	56.0	55.8	55.9	55.8