Earnings per share (Tables)

3 Months Ended

Mar. 31, 2012

Earnings per share

Computation of basic and diluted earnings per share

($ in millions, except per share data)		2012		2011
Numerator:
Net income	$	766	$	524
Denominator:
Weighted average common shares outstanding		498.7		531.0
Effect of dilutive potential common shares:
Stock options		2.0		2.2
Restricted stock units and performance stock awards (non-participating)		0.8		0.4
Weighted average common and dilutive potential common shares outstanding		501.5		533.6
Earnings per share - Basic	$	1.54	$	0.99
Earnings per share - Diluted	$	1.53	$	0.98