Per Common Share Information	6 Months Ended
Jun. 30, 2017
Earnings Per Share [Abstract]
Per Common Share Information	Per Common Share InformationDiluted earnings per common share is calculated using net income divided by diluted weighted-average shares. Diluted weighted-average shares include weighted-average shares outstanding plus the dilutive effect of share-based compensation, calculated using the treasury stock method, of 7.6 million shares and 7.2 million shares for the quarters 2017 and 2016, respectively, and 7.1 million shares and 7.4 million shares for the six months 2017 and 2016, respectively. Stock options that would have been antidilutive, and therefore were not included in the calculation of diluted weighted-average shares, totaled 0.1 million shares and 4.2 million shares for the quarters 2017 and 2016, respectively, and 4.0 million shares and 3.4 million shares for the six months 2017 and 2016, respectively.

Per Common Share Information

6 Months Ended

Jun. 30, 2017

Per Common Share InformationDiluted earnings per common share is calculated using net income divided by diluted weighted-average shares. Diluted weighted-average shares include weighted-average shares outstanding plus the dilutive effect of share-based compensation, calculated using the treasury stock method, of 7.6 million shares and 7.2 million shares for the quarters 2017 and 2016, respectively, and 7.1 million shares and 7.4 million shares for the six months 2017 and 2016, respectively. Stock options that would have been antidilutive, and therefore were not included in the calculation of diluted weighted-average shares, totaled 0.1 million shares and 4.2 million shares for the quarters 2017 and 2016, respectively, and 4.0 million shares and 3.4 million shares for the six months 2017 and 2016, respectively.