Stockholders' Equity (Stock Option Activity) (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Options Outstanding - Number of Shares
Balance as of December 31, 2014 (in shares)	7,240,419
Granted (in shares)	0
Exercised (in shares)	(1,736,987)
Forfeited/canceled (in shares)	(266,388)
Balance as of September 30, 2015 (in shares)	5,237,044
Exercisable as of September 30, 2015 (in shares)	4,768,764
Exercisable as of September 30, 2015 and expected to vest thereafter (in shares)	5,181,225
Options Outstanding - Weighted-Average Exercise Price
Balance as of December 31, 2014 (in dollars per share) | $ / shares	$ 215.56
Exercised (in dollars per share) | $ / shares	191.10
Forfeited/canceled (in dollars per share) | $ / shares	311.31
Balance as of September 30, 2015 (in dollars per share) | $ / shares	218.80
Exercisable as of September 30, 2015 (in dollars per share) | $ / shares	209.30
Exercisable as of September 30, 2015 and expected to vest thereafter (in dollars per share) | $ / shares	$ 217.75
Options Outstanding - Weighted-Average Remaining Contractual Term
Balance as of September 30, 2015	3 years 9 months 22 days
Exercisable as of September 30, 2015	3 years 7 months 9 days
Exercisable as of September 30, 2015 and expected to vest thereafter	3 years 9 months 22 days
Options Outstanding - Aggregate Intrinsic Value
Balance as of September 30, 2015 | $	$ 2,120
Exercisable as of September 30, 2015 | $	1,976
Exercisable as of September 30, 2015 and expected to vest thereafter | $	$ 2,103