Earnings Per Common Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The effect of dilutive securities on the weighted average common shares outstanding included in the calculation of earnings per diluted common share for the three and nine months ended September 30, 2017 and 2016 were as follows:

	Three Months Ended September 30		Nine Months Ended September 30
(number of shares in millions)	2017	2016	2017	2016
Weighted average common shares outstanding	256.4	266.3	257.0	267.0
Effect of dilutive securities:
Stock options	1.0	—	1.0	0.8
Other stock compensation awards	0.8	—	0.8	1.0
Potentially dilutive common shares	1.8	—	1.8	1.8
Adjusted weighted average common shares outstanding	258.2	266.3	258.8	268.8

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

The effect of antidilutive securities on the weighted average common shares outstanding excluded from the calculation of earnings per diluted common share for the three and nine months ended September 30, 2017 and 2016 were as follows:

	Three Months Ended September 30		Nine Months Ended September 30
(number of shares in millions)	2017	2016	2017	2016
Effect of anti-dilutive securities:
Stock options	0.5	0.6	0.6	0.6
Other stock compensation awards	—	1.8	—	—
Potentially anti-dilutive common shares	0.5	2.4	0.6	0.6