Stock Based Awards and Other Equity Instruments - Summary of Stock Option (Details) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Options Outstanding
Options Outstanding, Beginning balance | shares	8,651
Options Outstanding, Granted | shares	396
Options Outstanding, Exercised | shares	(2,759)	[1]
Options Outstanding, Cancelled or expired | shares	(243)
Options Outstanding, Ending balance | shares	6,045
Options Outstanding, Exercisable | shares	2,593
Options Outstanding, Vested and expected to vest | shares	5,931
Weighted Average Exercise Price per share
Options Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 44.47
Options Granted, Weighted Average Exercise Price	85.70
Options Exercised, Weighted Average Exercise Price	33.78	[1]
Options Cancelled or expired, Weighted Average Exercise Price	52.73
Options Outstanding, Weighted Average Exercise Price, Ending balance	51.72
Options Exercisable, Weighted Average Exercise Price	35.97
Options Vested and expected to vest, Weighted Average Exercise Price	$ 51.34
Weighted Average Remaining Contractual Life and Aggregate Intrinsic Value
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 9 months 18 days
Options Exercisable, Weighted Average Remaining Contractual Life	4 years 10 months 24 days
Options Vested and expected to vest, Weighted Average Remaining Contractual Life	5 years 9 months 18 days
Options Outstanding, Aggregate Intrinsic Value | $	$ 106
Options Exercisable, Aggregate Intrinsic Value | $	74
Options Vested and expected to vest, Aggregate Intrinsic Value | $	$ 105

[1] Inclusive of 1,769,209 options which were not converted into shares due to net share settlement in order to cover the aggregate exercise price and the minimum amount of required employee withholding taxes. Potential shares that had been convertible under stock options that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited consolidated statements of cash flows.