Earnings per share (Tables)

12 Months Ended

Dec. 31, 2013

Notes To Financial Statements [Abstract]

Earnings per share reconciliation

The following table provides a reconciliation between basic and diluted earnings per share:

In millions, except per share data	Year ended December 31,		2013		2012		2011
Net income		$	2,612	$	2,680	$	2,457
Weighted-average shares outstanding			843.1		871.1		902.2
Effect of stock options			3.0		4.3		6.7
Weighted-average diluted shares outstanding			846.1		875.4		908.9
Basic earnings per share		$	3.10	$	3.08	$	2.72
Diluted earnings per share		$	3.09	$	3.06	$	2.70