Earnings per share (Tables)

3 Months Ended

Mar. 31, 2013

Earnings per share

Computation of basic and diluted earnings per share

($ in millions, except per share data)		2013		2012
Numerator:
Net income	$	709	$	766
Denominator:
Weighted average common shares outstanding		475.4		498.7
Effect of dilutive potential common shares:
Stock options		3.7		2.0
Restricted stock units and performance stock awards (non-participating)		1.7		0.8
Weighted average common and dilutive potential common shares outstanding		480.8		501.5
Earnings per share - Basic	$	1.49	$	1.54
Earnings per share - Diluted	$	1.47	$	1.53