Income per Share Income per Share (Tables)

12 Months Ended

Dec. 31, 2018

Weighted average shares outstanding and antidilutive shares [Line Items]

Weighted average shares outstanding and antidilutive shares [Table Text Block]

A reconciliation of the number of shares used for the basic and diluted income per share computations is as follows:

	Year Ended December 31
Millions of shares	2018	2017	2016
Basic weighted average common shares outstanding	875	870	861
Dilutive effect of awards granted under our stock incentive plans	2	—	—
Diluted weighted average common shares outstanding	877	870	861
Antidilutive shares:
Options with exercise price greater than the average market price	14	6	11
Options which are antidilutive due to net loss position	—	2	1
Total antidilutive shares	14	8	12