Earnings Per Share - Reconciliation of the number of shares used for Basic and Diluted EPS (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding for basic EPS	438	437	443
Effect of dilutive securities - stock plans	0	2	1
Adjusted weighted average common shares outstanding for diluted EPS	438	439	444
Anti-dilutive shares excluded from diluted EPS
Anti-dilutive shares excluded from diluted EPS
Future potentially dilutive shares excluded from diluted EPS (2)	2	0	0
Future potentially dilutive shares excluded from diluted EPS
Anti-dilutive shares excluded from diluted EPS
Future potentially dilutive shares excluded from diluted EPS (2)	3	2	4