Stock Based Awards and Other Equity Instruments - Summary of RSU Activity (Details) - Restricted Stock Units $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
RSUs outstanding
Unvested RSUs outstanding, Beginning balance | shares	1,750
Unvested RSUs, Granted | shares	2,016
Unvested RSUs, Vested and released | shares	(627)	[1]
Unvested RSUs, Cancelled | shares	(283)
Unvested RSUs outstanding, Ending balance | shares	2,856
Weighted Average Grant-Date Fair Value Per Share
Unvested RSUs outstanding, Weighted Average Grant-Date Fair Value Per Share, Beginning balance | $ / shares	$ 79.02
Weighted Average Grant-Date Fair Value Per Share, Granted | $ / shares	63.71
Weighted Average Grant-Date Fair Value Per Share, Vested and released | $ / shares	76.02	[1]
Weighted Average Grant-Date Fair Value Per Share, Cancelled | $ / shares	73.06
Unvested RSUs outstanding, Weighted Average Grant-Date Fair Value Per Share, Ending balance | $ / shares	$ 69.35
Aggregate Intrinsic Value
Unvested RSUs outstanding, Aggregate Intrinsic Value | $	$ 132

[1] Inclusive of 173,429 RSUs withheld to satisfy employee minimum tax withholding requirements due to net share settlement. Potential shares which had been convertible under RSUs that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive 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 consolidated statements of cash flows.