Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

A summary of the status of our options as of Dec. 31, 2015, and changes during the year, is presented below:



Stock option activity	Shares subject to option		Weighted-average exercise price		Weighted- average remaining contractual term (in years)
Balance at Dec. 31, 2014	48,420,255		$	33.06	4.2
Granted	—		—
Exercised	(10,862,315	)	30.15
Canceled/Expired	(1,822,676	)	40.36
Balance at Dec. 31, 2015	35,735,264		$	33.57	3.4
Vested and expected to vest at Dec. 31, 2015	35,734,694		33.57		3.4
Exercisable at Dec. 31, 2015	33,703,283		34.27		3.2



Stock options outstanding at Dec. 31, 2015
	Options outstanding					Options exercisable (a)
Range of exercise prices	Outstanding at Dec. 31, 2015	Weighted-average remaining contractual life (in years)	Weighted-average exercise price			Exercisable at Dec. 31, 2015	Weighted-average exercise price
$ 18 to 31	19,256,469	4.9		$	25.78	17,224,488		$	26.22
$ 31 to 41	6,044,363	1.0		39.73		6,044,363		39.73
$ 41 to 51	10,434,432	2.0		44.38		10,434,432		44.38
$ 18 to 51	35,735,264	3.4		$	33.57	33,703,283		$	34.27


(a)	At Dec. 31, 2014 and 2013, 42,137,574 and 52,130,525 options were exercisable at an average price per common share of $34.38 and $34, respectively.



Aggregate intrinsic value of options (in millions)	2015		2014		2013
Outstanding at Dec. 31,	$	306	$	409	$	336
Exercisable at Dec. 31,	$	267	$	307	$	212

The following table summarizes our nonvested PSU, restricted stock and RSU activity for 2015.



Nonvested PSU, restricted stock and RSU activity	Number of shares		Weighted- average fair value
Nonvested PSUs, restricted stock and RSUs at Dec. 31, 2014	21,400,291		$	27.72
Granted	6,948,487		39.58
Vested	(10,880,844	)	25.34
Forfeited	(483,963	)	33.20
Nonvested PSUs, restricted stock and RSUs at Dec. 31, 2015	16,983,971		$	34.07