Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

Stock-based compensation for the three months ended March 31 is as follows:

(in millions)	2013		2012
Stock option expense	$	2	$	5
Restricted stock and unit awards expense	19		12
Total stock-based compensation expense	$	21	$	17