Earnings Per Common Share (Tables)

6 Months Ended

Jun. 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 six months ended June 30, 2017 and 2016 were as follows:

	Three Months Ended June 30		Six Months Ended June 30
(number of shares in millions)	2017	2016	2017	2016
Weighted average common shares outstanding	257.1	267.2	257.4	267.4
Effect of dilutive securities:
Stock options	1.1	0.9	1.1	0.9
Other stock compensation awards	0.8	1.0	0.8	0.9
Potentially dilutive common shares	1.9	1.9	1.9	1.8
Adjusted weighted average common shares outstanding	259.0	269.1	259.3	269.2