Income per Share Income per Share (Tables)

12 Months Ended

Dec. 31, 2016

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	2016	2015	2014
Basic weighted average common shares outstanding	861	853	848
Dilutive effect of awards granted under our stock incentive plans	—	—	4
Diluted weighted average common shares outstanding	861	853	852
Antidilutive shares:
Options with exercise price greater than the average market price	11	10	2
Options which are antidilutive due to net loss position	1	2	—
Total antidilutive shares	12	12	2