Earnings Per Share and Shareholders' Equity Transactions (Information Regarding Basic and Diluted Earnings Per Share) (Details) - $ / shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Basic shares used in the calculation of earnings per share	42.4	42.7	42.5	42.8
Diluted shares used in the calculation of earnings per share	42.9	43.0	42.9	43.3
Per share effect of dilutive securities on income from continuing operations	$ (0.01)	$ (0.01)	$ (0.03)	$ (0.04)
Per share effect of dilutive securities on net income		$ (0.01)	$ (0.03)	$ (0.05)
Employee Stock Option [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive effect of securities	0.3	0.2	0.2	0.3
Non-Vested Stock Grants [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive effect of securities	0.2	0.1	0.2	0.2